Charging to 80% actually hurt my battery?

Just wanted to share something interesting and counterintuitive.

My wife and I have an iPhone 16 pro. She sets her max charge to 100% while I set mine to 80%. We both have optimized charging and about 300 cycles.

Here’s what’s surprising: Her maximum capacity is still at 100% while mine is 96%!

I thought bc I’m only charging up to 80% that I would have better battery life.

Anyway, I’ve now set my max charge to 100% and stopped caring about maximum capacity.

Side note: I’m wondering now if I should do the same for my Tesla and just set the max charge to 100% and not care. I currently set it to 80%.