I would like garminconnect to register personal best from more workouts than run, bike, swim.
i would like it to save personal best at distances in every sport you can choose from on the watch.
I'd just be happy if the watch didn't forget those things after either doing a factory reset or buying a new watch. At this point a cloud system that syncs your data for at min the last 30 days to a new or reset device should be a thing. That would include personal bests, but yea, beyond that, what particular sport(s) would you want with that?
For records/personal bests, copy the contents of /GARMIN/RECORDS from your old watch to /GARMIN/NEWFILES on your new watch. (Using a USB cable.)
You can also send records from GC to your device.