Garmin will likely keep me because running gps for 10+ hours at a shot is important. A full smart watch is far less of a priority.
If you don't want to dive headlong into Apple's stuff, then a Garmin might very well be all the smart watch you need. It's been quite a few years since I used a Garmin as a full-time smart watch, but you can have notifications and messages (read-only if using an Apple phone) and even contactless payment on a Garmin. If we weren't a knees-deep Apple house, I'd just use my Garmin 945 as my smart watch.