For Eternatus, the poison from Garbodor won't help much. 4-0-1/4-0-2 Obstagoon line with a couple candies is going to help out the damage more as well as give you a couple free wins against basic-only decks. And you'll find that it's not easy to get 8 Pokémon on your bench turn two, nor do you need to in most cases. As for Toxitricity, ideally Garbodor would be the bench sitter, but in reality it's not that easy to set up a stage one on the bench by turn 2 while also attaching an energy every turn. Garbodor will still be played in many Toxitricity lists, but a backup like this is very good. If this has a 2 retreat cost so it works with air balloon, it's equally as good as Garbodor. It's not easy to setup a stage one right away every game while needing to attach every turn and not being able to play a supporter on turn one in half the games you play. This card can be grabbed whenever by a simple Quick Ball and can turn a switch into a Hypnotoxic Laser. I'd argue that it's significantly better than Garbodor.