Culinary mushrooms aren't the only kind you can grow. Psilocybe mushrooms are the absolute easiest to work with and grow so cheaply that I just give them away, reishi/cordyceps/turkey tail all make powerful medicinal teas/tinctures, and there are mutualistic fungi that boost plant health in your garden like red wine caps. Working with a different kingdom that's more like ant farms than vegetables is really fun shit that will come in handy when meat is no longer affordable.