Agreed, I'd say one is a smartwatch, the other is a fitness tracker. The Garmin can't make calls or send text messages, for example. Most don't even have NFC or wifi, although the Felix 6 pro does, but it's also quite a lot more expensive than the 6, let alone the SE. The resolution is typically about half as much, the screen size is smaller, thicker, heavier, brightness is lower, and the screen to bezel is much worse. It's just not something I'd wear with a suit to the office, or at a dinner, or when I go clubbing because it just doesn't look very nice. It's something I'd wear during workouts. But because of that, it's more limited in use, has less value, and isn't quite worth the price for me. It also means I'm not wearing it all day, so it won't give me all-day health data tracking. Dancing for 4 hours at a party would get tracked, heartrate, calories etc, on my apple watch. But I wouldn't bring the garmin felix 6 pro to such an occasion. (there's smaller versions but I find their specs/feature set is a lot worse).
As a fitness tracker I'd say it's superior to the apple watch.