When Skyrim came out, it did not take long until a sizable number of people seemingly spent more time with mods and just walking around than actually playing the game. A friend of mine mocked this by saying that he could just take a walk in a forest instead. Yet, if you do not live close to nature, this is not an option for you, so the make-believe world of Skyrim in 2011 probably scratched an itch for a lot of people who were not even aware that one of their fundamental needs was not met, i.e. spending time in nature.
There were several other landmark releases that reached a surprising level of commercial success, and those were sometimes games with somewhat flawed mechanics or dubious design decisions. First and foremost, I am thinking of The Witcher III and Zelda: Breath of the Wild. The Witcher III is mechanically lacking, but the world is quite beautiful. Back when I played it, I lived in a rather unsightly apartment complex, so the medieval world of this game was one I quite enjoyed escaping to, and I had some gaming sessions in which I ignored the main quest, and the many side quests, completely, instead opting to go on a virtual hike.
The Legend of Zelda: Breath of the Wild seemes to have a very similar effect on people. There are plenty of people who readily acknowledge that the game world is kind of empty, yet they still sink over 100 hours into it. The art style is not bad at all. I find the lush green meadows in this game to be beautifully realized. Here is a video of Link shield surfing that gives a pretty good illustration of these areas:
I can think of a few more games that put you in an environment that are very relaxing to be in, e.g. Dragon Quest XI, Kingdom Come: Deliverance, or Genshin Impact. Those are simply wholesome games. I wonder if there is more to my observation, though. It could well be that playing a game that is set in nature has very positive impact on your mental health whereas this effect is arguably a lot less pronounced when exploring the dystopian world of Cyberpunk 2077, for instance. In fact, in Western games, there used to be a trend to release completely drab games, devoid of any bright colors. This was particularly pronounced during the Xbox 360 era. You could almost think that Western video games are designed to make you feel down, and surely it is not a complete coincidence that both The Witcher III and Kingdom Come: Deliverance were made by Eastern European studios, and not Electronic Arts. Probably, The Witcher III could not be made by the current staff of the studio either, seeing how completely Westernized they have become.