Nowadays I find a lot of games feel like too much work and/or anxiety when I just want to relax for like, 30 minutes to an hour after a long day. On the other hand, the games specifically designed to help you unwind just feel boring imo.
In the past I've felt like Outer Wilds scratched this itch, cause the whole experience was engaging but generally relaxed. There was a mystery that kept me hooked and the exploration and movement was fun in and of itself. I also felt like Subnautica filled this role since it was very much at my own pace, with anxiety producing portions which could for the most part be avoided or minimized, and also there was a clear objective to fulfill, get off the planet.
So what games do you play when you just wanna relax?
Well I've been playing since closed beta so like 10y and something at this point, but you can definitely go over my MR fairly easily, MR is about collecting things not really skill related, of course there's still some time invested.
Easiest way would be to go to your codex, select a category, melee for example and make and level up every single weapon there, sentinels, warframes you get the idea, anything you can level up gives mastery, even completing the star chart by unlocking every mission, somethings will be harder or expensive to get or behind multiple days of farm aka most of stuff in open world but that's how everyone does it.