Frontend on old big product or frontend on new AI project?

Got asked if I want to move to a different team to do frontend work on a product you've heard of. Also got asked by someone else if I want to join a team doing frontend work on one of those new AI projects that started popping up since Google started worrying about openai. Both are frontend so I'm not sure it really matters career-wise that one is AI-related. On the other hand like 90% of my work has been full stack with like 99% of that being backend, and I only switched to frontend last year, so maybe the new AI project would give me an opportunity for some kind of backend-related 20% work? There are so many layers between my current project and the backend that there's basically no chance I could do anything full-stack where I'm currently at and I miss that. 8yoe L4 $255k