How do you guys charge your iPhone? Do you charge it to 100% or 80% Optimized charging?

Asking this because I am opting out of Apple Care+ and planning on keeping this for 3-4 years.

I have a 15 Pro Max and I charge it to 80%, but I need to charge it at least twice a day because it drains so fast and I charge it when it touches 20%. Anyone else having battery draining issue? Sometimes I just use Instagram for 15 minutes and it’s already down ~10%.