Does the amount of meshes/textures added by mods affect game performance, even if the related mod is not active?

For example, if I download MCA and NOM, both of which contain hundreds of extra meshes/textures, then install them in my game, but then deactivate the esps so that I'm just running vanilla. Do those extra mesh/texture files affect my game performance?

If they are not unique then they will act as replacers. So those will be loaded and affect performance.

There is also a theory that suggests the game goes through every file which can slow down things. So it is recommended to avoid bloating. This includes the installers folder of Mash.

I think no one has managed to slow down Morrowind via texture replacers yet but complex meshes destroy performance easily.

Loose files/missing/repeated/dirty records? I think it can force resorting and resorting which can make loading times very long. Tidiness always helped my performance.