Lets set a few things clear and stop Mis-using a term I will start out with a few clarifying terms.

1. pay wall- A pay wall generally has places and items that are not obtainable if you dont buy them
a. Primary example is DLC's and the jewelry crafting skills.
this may or may not make a difference in game play.

2. Quality of life enhancements- this class of things generally Enhances a players playing experience.
QOL items are things like Housing personal bankers etc and in ESO the craft bag.
Cosmetic costuming is such an item.
3. Pay to Win - this kind of stuff is Hard cash only unique Items that give the buyer A distinct and measurable advantage over non buying players.
Examples of this would be something like a super stat'ed weapon/armor etc that gives a flat out insurmountable advantage over players who have not bought that item.

This is the clarification of the terms now lets examine ESO specifically.

ESO definately has numbers 1 and 2 yet it has Zero of Number 3. Really people cosmetics have zero impact on fighting skills in PVP or PVE. You can not buy in the crown store that allows you to overwhelm your Piers. Yes they could speed past you on things like research timers and potentially get some items you have to wait on but this is not an overwhelming advantage.
Honestly a Motif or an outfit style or a mount or any other item in the crown store are flat out not pay to win..

While gold buying Is deplorable and should be curbed its general effect is moot yes it skews the economy a bit but its effect here in ESO is pretty limited.. Yea i get angry and some of the Obscene Prices on "pretties" but that is not isolate to eso but is rampant in every mmorpg ive played