Plenty of others in this thread have expressed the mistake of calling these sorts of activities "useless" but I can relate to the splendidness of self-expression for fun. I've recently started writing music and might record some songs soon after years of religious listening. Over that time I heard many amazing artists across all sorts genres, some with jaw-dropping virtuosity or unbelievable originality. And yet it took someone doing really lo-fi DIY recording over some simple songs to get me off my ass and learn to play. Even though they hadn't reached the heights of some of the other groups I'd heard, I could hear them having fun with their music in the recording, and that was enough to convince me I should give it a try.