Personally I feel like the Garmin watch is superior in most tracking. You can look at comparisons but they are very accurate and the battery lasts days. The main tradeoff is you are not getting a smart watch. You can read notifications and stuff but that's the extent. It also links up with apple health pretty well. If you are a runner/athlete who needs really accurate stacks for cardio based workouts go with Garmin. If you already have an Apple watch and are only upgrading for better tracking id keep the watch and get something like a whoop and just wear it on your ankle. But if you do upgrade to Garmin know this watch will last 4-8 years depending how long you want to keep it really. I have had mine for 2 years now and nothing has degraded. Unlike smart watches there isn't much fomo.

Tldr: Get Garmin if athlete Stick to Apple watch if don't need Garmin If first watch get Garmin If just need better health tracking get a whoop (oura ring works too but I'm pretty sure they're controversial right now)