To my knowledge every Argon2 coin is covered right no with the gpu-miners or you may know 'new' Argon2 coins that I don't know of.

Then the part of size; yes a GPU is smaller, but the heat is the bigger issue than the size of the component. In cooling systems (my rl work ironically) a large component is easier to cool... So I agree that it's harder to scale but not by much more. The GPU-rigs are about just as annoying to build and the heat of the systems (which is hash per watt eff.) is what will limit your building more than anything (if we're going to talk about building sized farms anyhow).

This is also where your assumptions go wrong. Just because someone can put 1 Mhs on a coin, if they're not cheaper in doing that they can't dump the coin for cheaper. At best their added effort makes the coin more valuable as they've made it 1 Mhs harder to mine. It's when a piece of hardware has a substantial advantage over another piece then it will hurt the coins value. This is what you often see when coins go to GPU stage, the initial GPU dumping before it settles and (hopefully) slowly comes back up with continued growth.

As for your last comment... simply hilarious! Thank you!
Mining through only the wallet and 1 wallet per pc, how do you expect that to happen? VM's / RPC connection or more broadly the entire blockchainnetwork means pools are possible by definition of having a network. Even if you 'block a virtual pc' a comment rather hilarious as your entire OS is already 'virtual' on top of hardware. These are things you can not prevent, at best you can make it not available at launch. Eventually it will be done and it will be available.

Same as that Elicoin is a very GPU-favoured coin that runs insanely efficient on the KlausT gpu-miner for Nvidia cards @ric9493968