Vileplume was just an example of something that'd be better. I could've picked a better one like Ampharos DRX or Altaria DRX or even Crobat PLS.
Of what you've said...
In general it does hurt that you can't hide your Evolving Basic on your Bench to Evolve safely, but that isn't an impossible hurdle to clear. Yes, some Pokémon become better when they can more easily hide on the Bench, but for most it still won't make them competitive... or it will risk breaking them. The "happy medium" is rare.
Vileplume is an example of something that clearly
won't be helped. Its problem isn't
Pokémon Catcher, it quadruples Weakness in a format where Weakness usually spells a OHKO and there aren't enough easy to splash in attackers where the quadrupling makes for an inexpensive, guaranteed OHKO.
Altaria is still vulnerable to
Escape Rope unless you're using a build I am unfamiliar with (if you are, please let me know! :lol
.
Altaria is also small enough that spread/snipe is a much greater risk; so every
Pokémon Catcher alternative is a threat to it!
Ampharos and
Crobat [Plasma] are also each still lacking; even with your proposed rotation we will still have some amazing attackers that will 2HKO something their size. The Ability or strategic sniping are required to score regular 2HKOs... and you don't have true control over that. Not only might your opponent use
Escape Rope to Bench
Ampharos (disabling Electromagnetic Wall), but the amount of damage involved can be tricky to time. You don't actively pick what gets damaged by Electromagnetic Wall, and if it doesn't shift the turns for a KO down, it will seldom matter.
Crobat [Plasma] has a useful Ability, but it isn't enough to make it a worthwhile Bench-sitter. As a Stage 2, it requires too many resources to swarm, and a single extra card isn't enough to justify running it as a low-count Bench-sitter. The Ability is only worth it if you can make it useful as an attacker and as the attack is already relying on Poison damage for its turn, you only get two extra counters from
Virbank City Gym. Why does that matter? Because it only hits 2HKO level with
Virbank City Gym in play. This also means most of the counters to the general
Hypnotoxic Laser/
Virbank City Gym combo are going to drop it back to a "so-so" attacker. Of everything you've named so far, this is probably the most promising.
tl;dr: So far all the examples you give aren't getting enough of a boost, and are arguably worse off without
Pokémon Catcher as current decks that rely on Bench-sitters will be better off.