I think it very much depends on the type of games you play. Some microtransactions or DLCs aren't just cosmetic.

I don't remember which game had mounts and extra inventory space as microtransactions, but they exist, and sure, they're optional, but it still kinda sucks that a player has to either grind for hours for rare RNG loot or just shell out 20$ for something that would make the game run better.

Single-player games aren't immune to this either. I still remember the fuck up that was Mass Effect 3's Day 1 DLC. Bioware insisted the character on the DLC was optional but many, including myself, felt that a character who represented a race that has been at the core of the series was absolutely necessary, and that his removal from the base game was a simple act of greed. Especially since he was ready to be played at the onset.