So many of the new mons seem like they were modelled in 3D first -instead of basing the models on concept art- or at least designed to make them easier to model in 3D, thus prioritizing very basic geometrical shapes that make them look very toy-like in nature and/or anatomically implausible. In some cases, it looks as though the different pieces that make up the Pokémon don't even fit together properly. It's not an issue of them not being "overdesigned enough", i.e. I'm not saying they need more spikes or stripes or what have you, it's mainly an issue with the basic shape of the monster.
Looking at these, I'm reminded of those companies that make plushies based on kids' drawings, who tend to use a lot of basic circles, squares and triangles and often draw their characters with very static limbs that lack joints.
Now, all this doesn't mean to say that it's impossible to like these designs or that there aren't mons in the dex that don't do this, it's just a trend I'm not particularly fond of; a design simplification that makes it harder to believe these are living creatures that inhabit the ecosystem presented in-game, and that it many cases just looks outright unappealing.