Exactly, I have a Galaxy watch myself and it does a fine job of tracking my sleep despite how old it is. They made Pokemon Go able to sync walking data with the system health app so they game could reward you even without it open. I don't know why they missed that for Pokemon Sleep, especially with all the delays
I'm really not a fan of this game because of having to leave your phone on all night long with it plugged in. For multiple reasons, but the fire hazard is definitely one of them. Why couldn't it sync up with other passive sleep trackers, like smart watches?
My most played games are Breath of the Wild, Animal Crossing New Horizons, Pokemon Violet, and now Tears of the Kingdom. And Mario Kart 8 Deluxe but I feel like that one's more of a multiplayer experience. Nothing else comes close to those on the Switch for me and I can recommend all of them.
I guess I can't know for sure, but I'd say it has to be Minecraft. I wish there was a way to see the hours I've spent in the Java Edition of the game. If it's not Minecraft though, my second guess would be Rocket League. When I add up the hours across the platforms I've played on, it comes out on top by a small margin.