My launch day Pro is charged in the same manner as yourself with the same sort of use during the day too and mine is also still showing 100% - I use the included fast charger.
Same here, 11 Pro Max just dropped to 99% health after 4 months.
Charging every 2 days, overnight by USB Anker charger and during the day by Samsung wireless car holder/charger.
To be fair, when I first got my 11 pro Max I was gaming and using it a lot. I used get screen on times of 8hrs and this carried on for a month. I start reducing my usage eventually. I guess it put a lot of stress no the battery.