How far did you get into Subnautica and what turned you off about it? I understand it’s not for everyone. It can be a little bit obtuse in the way it gates your progress behind radio transmissions, and if you don’t find the right blueprints your journey can be made much harder or easier respectively. I’ve been replaying it recently and I can see how it’d be hard to get into. One thing to note is that as you advance a lot of the annoyances of finding food, water & power to upkeep everything get eased through different technologies, so you slowly get more freedom from the grind, and the story is worth seeing to the end. In fact every new tech makes the game easier and faster and opens up the world that much more, either by making it easier to traverse long distances or go deeper, or carry more, etc. The early game is slow and frustrating in comparison.
I could cosign a bunch of suggestions already, but Outer Wilds is one of my favourite games of all time. I’ll try to explain it without any spoilers: It doesn’t gate your progress behind anything but your own curiosity and acquired knowledge. It also gives you a sense of freedom that you get from fully simulated physical movement in space. It is also deeply emotional and if you’re halfway to the end wondering, “How could they possibly stick the landing on this and end it well?” the answer is just trust, omg it’s so good. You can’t really experience it twice - it’s designed such that when you possess the right knowledge, you can finish the game extremely quickly, but also to do so you must truly understand and master the ideas you are being taught - so you can only experience it again by watching blind let’s plays. I’ve watched 4 so far and each one was a moving experience watching the person go through their own process of understanding over many, many hours.
If you like platformers, Teslagrad is a beautifully illustrated and impeccably designed metroidvania which I’ve played through many times. All the story is delivered through puppet shows rendered within the levels themselves and gorgeous collectible cards. They’ve just released a remastered version with a number of QoL changes that I’ll be playing again, and the sequel is out. I believe they’re still available in a Fanatical bundle right now.
The metroidvania that got me into the genre is actually a free game by the maker of Celeste, from many years ago. It’s called AnUntitledStory and I’ve played it through many times. Some quite hard platforming challenges but the whole aesthetic is extremely cute, and as you’d imagine from the dev of Celeste the controls are crisp and precise.
Hollow Knight is another incredible metroidvania/souls like. You play as a bug in the ruins of an ancient civilisation of bugs and it is quite haunting. Again, amazing aesthetic.
And if you want something chill instead, I’d go with Spiritfarer. You build your boat and travel the spirit world helping souls on their journey to the afterlife, except each soul is unique and has their own personal needs and closure you help them achieve before they’re ready to pass. Most importantly you can pet your cat whenever you want, which every game should have.