>>58213980 (OP)
>cat is more slender than a toad
imagine my shock. i can't deny the broad bobblehead trend in the series (which actually peaked in gen 6 and has been on a decline since then) but this is a really bad example. factoring in what animal they're meant to be, bulbasaur's head-to-body size ratio is actually pretty similar to sprigatito's, and if you made an even more apt comparison - say, meowth and sprigatito - you'd find their proportions are basically the same.
a comparison i like to consider is between the two in picrel, because they actually do show a stark difference in aesthetic sensibilities through the years. that said, i think all it speaks to is how the series has evolved over time. it's not like things were ever gonna stay exactly the same, they aren't even the same now as they were 12 years ago - people's reactions to the new megas should tell you that much.
seriously ask yourself, when was the last time we had a mon with the proportions of helioptile? maybe an outlier or two like nickit in gen 8? honestly as soon as gen 7 the pendulum started to swing back in the direction of normal proportions, in hindsight i could have put salandit in this image too to hammer that point home.
>tl;dr the only constant is change, and that's ok