My 14 Pro Max, which I got on launch day, is at 97% health.
I charge it every night on a Belkin 3-in-1 MagSafe charger (same one we recently saw an article about), and often keep it on an identical charger at my desk (I like the display, often I'm playing music from the phone to my Home Pods and like to have the image there of what's playing). Other than the the Belkins, I'll have it connected to a lightning charger in the car when driving around.
I don't pay too much attention to what kind / when /etc of charging I do; I let the phone decide how to manage its own charge. Seems to have done a great job so far.
I wonder if the phones that are seeing significant degradation are in hot locations when charging, etc. This can be bad for battery health.
Oh, and I never use a case on my phone which might have an additional benefit of keeping the phone a little bit cooler while charging.