Great write up. I am very much like you. I've had an Apple Watch since S0 and currently have the S7. I recently purchased a Garmin Fenix 7x as I had taken up running and was interested in the training, recovery and other features.
I went running with it a few times and loved a number of things about it. The physical buttons to swap between screens. The ability to change the amount of info on each screen (I know you can change the info on the Apple Watch but you can't change the size the info is shown). Maps that are downloadable to the watch and can show routes (hopefully apple adds this with the new maps they have in the future). I also loved starting a training plan and having the next run show up on the watch.
Ultimately I returned the Fenix as I couldn't justify having the Apple Watch and the Fenix. I also missed having podcasts, music and audiobooks while on a run as all of that is with Apple right now (lock in is real).
I had a fenix too. I bought it when I was running like a maniac, and biking occasionally. I liked that it would connect to the many ANT+ sensors I had, and had other features like auto-start, and could do just about any sport I could think of doing. And then, fate hit. I blew my foot and needed surgery and that pushed me over the line to sell it. However that wasn't the main reason I decided to dump it.
The fenix was that Swiss Army Knife that had ALL THE BLADES. It had so much that it seemed to nearly require an advanced degree to set it up. It was so complicated. Sure, I loved the screen, and the fact that it could be used on a bike ride, but looking at my wrist for speed and distance was getting really uncomfortable. I also occasionally had to hit a button too. Taking my focus off the people around me and the terrain that I was on really freaked me out. (And it was HEAVY!!)
So not having the ability to run, and feeling very uncomfortable while riding, I sold it and got Garmin's Edge 1030. It does so much, it's a bikers Swiss Army Knife, and has so much capability, and I haven't scratched the surface.
So I got an Apple Watch, and haven't looked back on that brand. I wish it had better battery life, for sure, but it *can* do quite a lot. I use it for weight training, and walks, and have used it a few times for rides, and also capturing mowing, which is a hoot. People are amazed with how long it takes me to mow my lawn.
This isn't to dump on the Garmin, or other brand, sport watches, but if you end up only doing a couple activities and for limited times and levels, the Swiss Army Knife is likely overkill. And frustrating. I went to the Garmin Store a few times for help getting it working, and after they closed all of them, went to hassle the sales droids at whatever store would let me in.
As far as music, I was told that I could put *some* music on my fenix, but never figured out how, and thought that it would be so limited to be rather useless.
So, at least to the time being, I'm invested in the Ring System, and realize the capability of the other watches out there, but am happy where I am. If something changes, like the ability to start jogging, I might consider a better device, but...