What is it that does it for Fenix versus Apple Watch?

Agreed on all points.

As I admit I most probably have a bias towards the apple ecosystem in general and their devices (even knowing they work great and have great quality, out of the question) considering them more shiny garmdgets than useful tools, it is certainly true that a part of apple more enthusiast people are biased to think whatever it's not done by apple is not worth doing...

No idea what an AppleWatch can do, I decided against the Apply system back then when the first IPhone didn't support UMTS while other devices did. It was a rather limited, not practical OS with 0 customization options and not even able to mail files it didn't know (I don't care that you can't open that Excel file, just attach it to the damn mail). So some stuff might (hopefully) have improved over the years. Also didn't like the first Androids, I think I got in with Android 4. Till then I kept using my Windows Mobile 6 smartphone.

No Idea how much I need the phone to enjoy the watch fully. Guess I can't view the watches data on an Android phone, maybe only in the browser.

So battery runtime is a clear winner for Fenix (I would be super annoyed having to charges my watch multiple times a week), I can record GPS-only for over 3 days without rest.
How good is the readability of that AW display in full sun? Fenix is perfect.
Does it have multiband GPS?
Can it withstand 10ATM water pressure?
Can the AW guide me through my pre-created strength trainings, count pauses and reps, show next exercises and weights?
Can I record my bouldering sessions vor later analysis if I make progress?
Can I view notes while recording paddle activities?
Can I store bar and QR codes on it (probably)?
Does it record Inline Skating activities?
Does it have a Badminton score counter?
Does it tell my how much additional kcal I used during my activities so I can see that I eat more to keep my form?
And yes all that data is important for people that want a basis to compare their progress in different sports, and the watch knows a lot of sports.

I have no idea what the AW can do, never touched one, but I doubt it can do much that I miss on the Fenix. But what do you think does the AW better?

In this world I would pick between just two options no 1 Garmin, no 2 Suunto. To me they look as proper watches, Im too old for toys. 

For me, I don't need a smart watch with which I can do all sorts of things. I want a sports watch that I can use for a multitude of sports, and that runs at least 10 days. Plus moar data! I guess comparing both watches is beside the point as both are aimed at different people and different uses: a smart watch with some sport features vs a sports watch with some smart features.

Battery of 29+ days is a gimmick??? Hahaha. Ok. 

Apple Watch is a fantastic device when it is not sitting on a charger. Although to be fair no smart watch can touch Apples HR measurement, phone calls and music streaming over cellular. 

elevate 4 in the fenix 7 isn't exactly inferior.

Waiting for tests from the heart rate sensor

I have an Apple Watch Series 7 sitting in my drawer, and a fenix 7x sapphire solar on my wrist. The AW is nice if you want a smartwatch with some basic health/fitness features. I learned very quickly that if you want the AW to have even a fraction of the fitness features of the fenix, you would have to download multiple apps (that don't always behave well with one another), and still would not come close to what you get from the fenix (and everything is in one place). That in combination of having to charge the thing at least once a day is a deal breaker.

JMHO.