The way I always considered it:
Open marketplace for game creators. That doesn't require payment up-front and a grueling approval-phase, where if you get denied there is no possibility for appeal, even with changes (yes I'm looking at you Steam). All this, if you follow our guidelines and policies... be real, its 2025 and you need to accept a ToS and cookies to unlock your front-door. I have never considered Itch to be a completely "open" marketplace that just blanketly allows any form of content no matter what.