Try it, Mate! If you don´t like it you can easily kick out the files from your game Folder. How to install reshade you just need to follow Post #2 here in Anth´s thread. AFter installing reshade successfully, there is one additional step to do. You must rename the "dxgi.dll" File into "D3D11.dll" where you can find now in your game Folder. This is necessary to run reshade with FIFA 23. Last step would be you must run Live Editor always before you run your game. It´s needed to inject reshade (D3D11) File into your game. In game you will see now in the top left corner a notification that reshade is successfully loaded.
If you need any assistant feel free to ask me or Anth. Here or via PM. I am glad if I can help you.
Oh, and to answer your question directly: Yep, Reshade is easy to install. It didn´t make anything to your game Folder. And easy to uninstall if you don´t like it. But trust me, once you have seen what it pimps up your game visually you will not miss them imo. haha
Works best with 6ons1 eSIM mod where you can find here:
https://www.patreon.com/posts/fifa-23-esim-mod-74032924
On top by using eSIM mod too, your Game Performance improves through the containing Performance mod.