I’m a tech guy, Apple guy AND mechanical watch guy.
Unless you have a specific use case in mind… you don’t need an Apple Watch.
Compared to a mechanical, the Apple Watch, as a daily driver sucks. An entry level Seiko mechanical will outclass it any day. Apple Watch is well designed and very well made… but it looks goofy to a watch guy.
The Apple Watch isn’t going to do anything for you on the bike that your head unit/power meter/HR strap doesn’t already do.
If you run or swim (in addition to riding)…a Garmin Forerunner 235 is a better choice in everyday.
If you just want activity tracking (step counting, etc) and you have an iPhone…your phone already does that (check Apple health, you’ll see). Or look at smart rings… Oura or Motiv… which you can wear WITH your mechanicals.
If you want more comprehensive general fitness tracking look at Whoop…with does recovery via HRV AND sleep tracking which will round out the analytics you get on the bike very well.
Apple Watch is a great product…but athletes are not the target. The software on it really has been fine tuned to get people moving… people are are not athletes and/or casual exercisers… which are not those people on this forum generally or a cyclist. This is even more the case since most 3rd party apps and the app ecosystem for the watch are going away. It tracks a lot of data but doesn’t play well with our training software ecosystems. Stava support on the Apple Watch has gotten worst and worst to the point its almost not even there anymore. Logging runs or swims using the onboard Apple software… is actually best in class experience and visually… but good luck getting that data into anything else without jumping through hoops and 3rd party apps on your phone to move the files.
Being able to make a call on your wrist is cute once and you’ll never do it again, the watch is not enough to leave the house without your phone (other than emergency needs) and battery life its till an issue. Notifications and alerts on your wrist are honestly annoying and you won’t use them after a few weeks.
(Full disclosure… I have owned every Apple Watch, currently have a Apple Watch 4… that I REALLY tried to make work for what I need and recently gave up on it and gave it to my wife to track her HIIT workouts… I run with a Garmin Forerunner 235 which is light years better for running… and stick to my beloved Seiko or Tissot mechanical for daily wear). My wife and I also both wear Motiv rings as our wedding rings… though I only use it for sleep tracking.)