The OP has a point - inflationary increases are likely to outstrip income generated - but the answer isn't necessarily related to BTL properties. I started out my professional life in property in the highly inflationary 1970's and trained withe the old Greater London Council. They offered loans/mortgages to people and weren't as hard-nosed as commercial lenders. Accordingly, many people took out loans to buy property, never paid a penny piece back to the Council and waited for foreclosure which, as it was the Council, took ages. Thus they were able to live in the property free and then pocket the profit once it was repossessed, sold and any arrears paid off.
I'm not recommending this as a course of action, but if you're going to buy a property and leave it empty, you may as well live in it for free. It's a win/win!