I'm still using a Forerunner 935 from 2017 and I haven't had any problems with charging/syncing data. I use the USB charger about once a week. Once every two weeks during winter when I don't use the GPS as much.

Only thing I have updated on the watch is the free loop, which holds the watch band after you've threaded it through the buckle. I'm gonna have to replace the watch band eventually - the plastic band is starting to crack, Canadian winters aren't gentle on these things.

Garmin support sent me replacement free loops when I called in asking how I could replace them.