Is self storage still a viable business?

Seems like the secret has been out for a while now about it being a cash flowing machine and prices are crazy high to buy an existing self storage business or rates are high if I'd want to start one, plus there's lots of competition. I know it depends on the area and how well you can manage it but is it something I should look into with no experience? I have the time, money, and will to learn. I've also heard about RV and boat storage as well. Would you recommend one of these options as the best? I'm guessing that boat and RV storage may be more seasonal, depending on your location. Thanks!