I think many are built without the use of gen ai to create assets. Obviously, the term "AI" is flexible enough that you could clarify every piece of software as involving AI if you wanted to, but I don't think that's productive.

I would assume that if a tool is there and the alternative too costly that they would use the tool instead of buring their project. Just today I stumbled over this for example, where they use GenAI as well: https://reddit.com/comments/1prqfsu