Still don't get it

I’ve been thinking about renting and the comments from my craft group. I still don’t get it though, because you don’t own it, you can’t change anything such as the paint color (and I don't mean from white to off white) on the walls. Maybe that explains something I read recently. The article was talking about how much harder it is currently for landlords to find tenants and mentioned that the average renter moves every 2 years. So I guess if you get bored with your surroundings you just move. I still don’t get it, the walls will still be white.