I have never really felt underwhelmed by a pokemon until Shield.
First up, there is Toxel - I thought this pokemon was gonna be the next Lucario or Zoroark. I was excited to finally get my hands on the egg because I thought it was gonna be the only one in game and then, oh.... they can be found in the wild... Not only that, but it had no moves at all. You couldn't train it like a normal pokemon. You had to send it in and bring it back. It felt like it took ages for me to get it to Lv 30. Until tonight, I thought there was something special needed like friendship, but guess not. I just didn't like the pokemon. I was excited for Toxtricity, but ended up not even using it. In fact, this was the first time I had almost used all old pokemon in a new generation game.
Applin was another pokemon. Much like Toxel, it had no moves and you couldn't evolve it for the longest time. And I just lost interest in it. I hate that I did. I really love Flapple. I was excited to use it, but by the time you get to the point where it could evolve, there was just no point to do so.
Gliscor is my favorite Pokémon overall. However Gligar is just too weak to bother training when you can typically catch him in game, and then by the time you get the trade evo, he’s just been a waste of a team slot for so long, it’s not even worth it anymore.