It's surprising more mushrooms aren't actively cultivated. One thing is the mycorrhizing kinds which are hard to farm, but there are plenty of types which just need the right substrate and some care. Lion's mane, which unfortunately doesn't grow in my country, is one, but there is also sulfur shelf a.k.a. chicken of the woods which I would have thought would be a great candidate for mass cultivation. Shaggy mane inkcaps have terrible shelf life, so I understand why those aren't cultivated, but it should also be fairly straightforward to do on a small scale.