From my understanding the stadia version of the game used pc servers so any account u had would just also already be on pc na or eu so just login from the game client like normal from a pc

You can essentially use a cloud gaming solution which just gives you access to a full desktop PC. Then you would install ESO from their site (you got it for free when stadia closed, everyone who had Stadia did), install it there and run ESO.
I can't vouch for anything as I've never did commercial cloud gaming (except to try out stadia (google gave a $10 discount on a game <$10 so I got it for free lol)) but I literally did a google search: best cloud gaming service and I found https://shadow.tech/.
Which is exactly what you need (solution-wise):
Again, I can't vouch or do anything for them, it's just what I found on google.
From my understanding the stadia version of the game used pc servers so any account u had would just also already be on pc na or eu so just login from the game client like normal from a pc
OP seems to be asking for a new cloud gaming solution on mobile using the PC servers now that Stadia is dead. Logging in from a PC is not a mobile cloud gaming solution.
I can sort of vouch for Shadow, been using it for years. But it is indeed a whole PC in the cloud, not just for a single game, and the price is accordingly: 30 euros a month. If the OP already has a PC that runs ESO smoothly than that's probably not a logical solution.