Recently my 2021 macBook gave me an alert that its battery was not charging past 80%. I took it to the Apple Store and because it had only been through 971 charge cycles, the battery was replaced for free.

I'm still waiting for 2023 MBP to hit that point. It's at 82% right now, with 67 cycles. It's been stuck at 82% for a few months now, though, stubbornly staying in the "normal" range.