Why Are the Cutest Starters Always the Worst

Cuteness is subjective. But then again, let me line up the strongest starters in every region based on fully evolved form and the type specialists (Read Gym Leaders and E4 members) in every region (And the cutest mons are based on my opinion)

Kanto
Bulbasaur is imo the cutest out of three and Venusaur is also the best to use in the Kanto games. Venusaur is strong against 4 out of 8 gym leaders (Rock, Water, Ground, Grass) and has 3 weaknesses (Ice, Fire and Psychic)
Blastoise is second best, since its strongest against 3 out of 8 gym leaders (Rock, Fire, Ground) and has 2 weaknesses (Grass/Electric)
Charizard is the worst. Only strong against 1 gym leader and 1 E4 member (Grass and Ice), while its weak against Rock, Water, Electric/Ground (Those 2 depend on Charizard or Charmander/Charmeleon).

While Venusaur has more weaknesses than Blastoise, it has more advantages. But the thing that truly elevates Venusaur over the other 2, is that Venusaur also resists Fighting (Bruno) and Surge (Electricity). And all starters pretty much resists the starter type they aren't weak against as well (And against their own type), which makes it Four resistances for Venusaur, against Charizards and Blastoise's 3.

In Johto, its really close between 2 (And only counting Johto, not the Kanto extension, since its post-game).
Typhlosion is the best, since it has no weaknesses and has three advantages (Bug, Ice and Steel).
Feraligatr is second best, despite having no weaknesses, it also doesn't have a specialty type its strong against.
Meganium. Chikorita is the cutest, but is the obvious worst mon (Arguably even the worst starter in a region ever), due to its glaring weaknesses (Poison, Ice, Flying, Bug) and no advantages.

In Hoenn, its not so close.
Mudkip is the cutest. However, Swampert has no speciality weaknesses due to its Ground typing, while itself is strong against Fire, Electric, Steel and Rock (And even if we take Steel away in Emerald it still the best).
Blaziken is second best, due to only having 3 weaknesses (Water, Psychic and Flying). It has five advantages (Rock, Normal, Dark, Steel and Ice) and 4 advantages in Emerald since then Steel away
Sceptile is the worst, due to it having 3 weaknesses (Fire, Flying and Ice), but also only has the advantage over Water and Rock

Sinnoh is funny, since all three starters have 3 type specialities they are weak against. So we have too look at the advantages.
Torterra is best since it has 6 advantages (Fire, Electric, Water, Steel, Rock and Ground)
Infernape has Bug, Rock, Steel, Ice, and Grass, as its advantages, which makes it the second best
Empoleon on the other hand, is only strong against Fire, Ground, Ice and Rock. Piplup is the cutest.

For Unova, Oshawott is the cutest.
Samurott is the best to use in the Unova games, since he has 2 weaknesses (Grass/Electric) in BW and 2 advantages (Ground/Fire) and in BW2 it has only 1 (Electric) weaknesses and 1 advantage (Ground).
Emboar is the second best mon to use in both Unova games. Has 4 weaknesses (Psychic, Ground, Flying, Water), but also has 5 advantages (Ice, Normal, Grass, Bug, Dark) in BW. Same weaknesses stay in BW2 and due to Ice and Grass leaving, losing two advantages.
Seperior is the worst to use in the Unova games. Has 4 weaknesses (Bug, Fire, Flying, Ice) and 2 advantages (Water and Ground) in BW. Its advantages stay in BW2, but it loses only one Weakness, despite Ice and Fire leaving, due to Poison being added. However, due to having more advantages and same amount of weaknesses, Emboar edges out Serperior.

Kalos. Fennekin is the cutest.
Delphox is the best. Has 5 advantages (Grass, Bug, Fighting, Ice and Steel). Has 2 weaknesses (Rock and Water).
Chesnaught is second best. Has 4 weaknesses (Fire, Psychic, Fairy and Ice) - Bug is neutral due to it being part Fighting. Has 3 advantages (Rock, Ice and Steel)
Greninja is the worst. Has 5 weaknesses (Grass, Fighting, Electric, Bug, Fairy). Has 3 advantages (Rock, Fire and Psychic).

Alola (Popplio is the cutest)
Primarina is the best. Has 3 weaknesses (Grass and Electric (Steel in USUM), but has 6 advantages (Fighting, Rock, Fire, Dragon, Ground and Dark - which in the Moon games it even has the advantage over Totem Raticate) in both games.
Incineroar is second best. Has 4 weaknesses (Water, Fighting, Rock, Ground). Has 3 advantages in (Ghost and Grass - USUM is adding Steel)
Decidueye reflects both Games. Has 4 weaknesses (Fire, Flying, Ghost, Dark). Has 4 advantages (Water, Ghost, Rock, Ground). However, considering Ghost is both weak and strong against eachother, it basically cancels eachother out, which makes me edging out Incineroar over Decidueye (But is pretty much interchangeable depending on ones interpretation)

For Galar, due to Switching Gym leaders of a different type (Which was only the case for 1 trainer speciality type in regards to weaknesses in Unova and Alola), i am putting in the Galar Starters for Both Sword and Shield (And Sobble is the cutest obviously)
Sword
Inteleon and Rillaboom are the best to use, due to having Inteleon only one weakness (Grass), but having 2 advantages (Fire and Rock) and Rillaboom is the same, with have Fire as its weakness, but the advantage over Water and Rock.
Cinderace is the worst. Has 2 advantages (Steel - Yes Chairman Rose counts cuz using one type of mon and Grass), but 2 weaknesses (Water and Rock).

Shield flips the tables, at least for Cinderace.
Cinderace is the best, cuz has 3 advantages (Ice, Steel and Grass) and 1 weakness (Water)
Inteleon is second best, due to having 1 weakness (Grass) and 1 advantage (Fire, since Rock isn't a thing anymore)
Rillaboom is the worst, due to having lost Rock as an advantage, but it has gained Ice weakness alongside Fire.

But in Galar, its really close regardless, so there is no wrong starter to pick in this region, depending on which one you deem cutest.

So as you see, depending on the interpretation of one starter being cuter than others, it pretty much doesn't matter if they are strong or not. The only one truly suffering is the Chikorita/Meganium and the only one having the superior advantage over the others in its region is Mudkip/Swampert (Since even if we don't count Swampert, Mudkip only has 2 weaknesses).

I also looked to take the Evil Bosses in this one, but the only bosses with a type specialty were either already covered (Giovanni being a Gym Leader), Maxie and Archie having types covered by gym leaders (Water and Fire), being neutral to all starters due to secondary typing (Guzma) and adding Guzma doesn't change the placement of Incineroar either. . The only one with a weakness over a starter that wasn't covered was Chairman Rose. You can Argue Cyrus is a dark type user, but considering its not clear, since he uses three Dark and three flying type mons in his final battle, i didn't think it was fair to include him as a flying entry or a dark entry due to that (And yes, the Ultra games don't count, cuz not in its own region).