I got deeply into this (genre?) when I burned out on a combination of playing big/tough games and the stresses of life. I also enjoyed the pace of Outer Wilds and Subnautica. Some other favourites:
Supraland 1/2 (low combat, light hearted metroidvania, I loved it)
Psychonauts 2 (amazing adventure game, big but not hard. I loved collecting everything, it was a great balance)
Tinykin (similar adventure, a bit like Pikmin, which is also great. Lots of chilled collecting)
Spiritfarer (lots of freedom, loose plot, not overwhelming)
Breath of the Wild (do what you want, very nice discovery elements)
TOEM, A Short Hike, GRIS and Cocoon (light adventure / puzzle games, peaceful but could be boring if you want action)
Yokus Island Express (lovely metroidvania, chilled gameplay, not overwhelming)
It Takes two (humour, light combat - played with my young son)
Unravel 1/2 (easy-ish puzzles)
Weirdly, I found Sniper Elite 4/5 fairly chill, lots of scoping out areas
Overcooked 2 (zero stress if you play practice mode a ton before attempting a level. I found it a very zen/flow game)
Peggle 1/2 (can be frustrating, but is very low stakes and arcadey. Lovely for short sessions)
Wilmots Warehouse (can be stressful if you take the timer seriously, but I loved all the organising. Very satisfying)
Vampire Survivors (can get a bit much, but pretty simple and disposable)
There are tons more, I deal with a lot of anxiety!
Some games I was recommended for this purpose that didn’t land for me:
Powerwash sim / other simulators (these feel like a second job for me. Constant grind and focus on perfection wasn’t helpful)
Tetris Evolution / Lumines (either gets too fast / hard, or gets boring)
Stardew / Terraria (in theory these look great, but I find huge sandboxes too overwhelming. Always feels like I should be doing more stuff / doing it better)
Roguelikes (I like Hades, Dead Cells, etc, but they’re very stressful and frustrating when so much hinges on survival)
Finally, I’d suggest trying a solo board game. More tactile and relaxing alternative to screen time.