Typical Apple stans here have never used a Garmin device to compare and don't know what it offers.
I have used several Garmin products (in fact I purchased three identical bikes for the three cities in which I spent the most time, so I could use the same Garmin bike computer without having to recalibrate it), but as soon as Wahoo Fitness came out with its Bluetooth sensors, I switched first to using my iPhone and than to my Apple Watch. I have played with more recent Garmin products, but have little motivation to switch because as Ray Maker says, they are really only useful for the time when I am working out, and quite inferior for all other smart watch uses. The UI/UX still sucks, and while they do provide some good data, I get enough using third party apps with my Apple ecosystem products.
Their devices are still FAR more dedicated fitness trackers than the Ultra, but okay, I guess they suck because they aren't Apple.
No, they are not competitive with the Apple Ecosystem, because they really only aspire to be dedicated fitness trackers. Everything else they do is just there to try to tick marketing boxes and since they UI/UX people are not even that good for performance tracking, they have no hope anywhere else. If all one cares about is tracking or one is willing to have two watches, they work fine. For those who do not want to put up with that, they really are not a viable option.
Their features are well above and beyond what Apple is capable of doing currently.
No. They offer longer battery life but give up many other things like LTE connections and an integrated ecosystem. They offer Ant+ but have a fraction of the fitness apps, and a minuscule selection of non-fitness apps. Apple's first party fitness tools are not as developed as Garmin's, but their third party ecosystem gets them very close.
On the other hand, Garmin's smart watch functionality is not even close to that of the Apple ecosystem, or to use your terms: Apple's features are well above and beyond what Garmin is capable of doing.