Here's another possibly* unpopular opinion.
(*Disclaimer: I have not statistically verified that this opinion is actually unpopular, I just suspect that some people may disagree)
Opinion: In terms of design, Gen V was the last time we got a reasonably well-rounded and "good" trio of starters.
Exhibit: The final-stage starters from Kanto forwards
https://bulbapedia.bulbagarden.net/wiki/Starter_Pokémon#Base_stat_comparison_when_fully_evolved
At first I found it difficult to pinpoint why I felt this way because I didn't think the later starters were always bad Pokemon designs, per se.
It took me a while to realize that the reason I liked later starters less was not because they were all "terrible" but because they seemed over-designed. We're used to very elaborately designed legendaries because they are powerful and (canonically) unique Pokemon. Yet it feels less appropriate to me when that design philosophy is applied towards starters. I think the starters should have a sense of being blank slates that grow with you throughout your journey. However, later starters have oddly specialized designs. It follows from that, that I'm usually OK with the relatively simple first starter stages. When they lose me, it's usually the third stage design that does it.
There were hints of the later starter design approach in Gen V, which was my cutoff point. Emboar was obviously inspired by sumo wrestlers, while Serperior was royalty and Samurott was a Samurai. However, the designs weren't uniformly anthropomorphic since Samurott was often seen in quadrupedal poses and Serperior was limbless. This helped to round out the trio somewhat and mask any uncanny "humanity", which is fine for oddballs like Mr. Mime and Jynx but seems less appropriate for starters that every player is given.
Fast forward to Gen VI and we see the tendencies hinted at in Gen V intensified. All three final stage designs are basically anthropomorphic, Delphox uncannily so. That is the only starter design I dislike viscerally (apologies to Delphox fans). While Chesnaught is OK on its own and Greninja is quite nice, taken as a trio there is a lack of variety. They all combine some animal inspiration with a blatantly human role (astronaut, oracle and ninja). This repeats again in Gen VII (archer, wrestler and opera singer) and Gen VIII (drummer, soccer player and spy). In this latest generation they're also more anthropomorphic than ever, as a trio.
I don't like this approach for starters. How can they intensify it further? Just use photos of celebrities? I'd love a generation where they return to giving us three creatures that evolve into more awesome creatures. I'm not totally opposed to human-like Pokemon designs but starters have special prominence because all players get one and they set the tone. It's Pocket Monsters after all, not Pocket Kids who want to grow up to be firefighters, policemen and pilots.
I'm going to elect president Phantump to Make Animals Great Again :P