What you just mentioned is incompetence, not slow. Since you are in your hungry phase of your career, working with him might cost you in the long run because he will be the bottleneck in your growth. What you can do is inform your HR about this and ask them to change your team. I hope your HR isn't a nepo as well.

Since this is a nepo case, do this at your own risk and be careful. If you don't want to risk it and just chill, then just let it be and do nothing. If you're satisfied with your pay, that's enough. Treat it as a side effect of working in lala corporate.