How does something like this take 30% of your time? On my calendar it's two hours out of 80, or 2.5%. One hour per sprint for planning, one hour for retro, why would it be longer?

My team lead spends more time prepping tasks with the PM prior to sprint planning, but even then it's about 5%.

My last company, we had one-week sprints, but we didn't do official retros, so it was still 2.5%, one hour of planning for 40 hours of work.