question: must one expect appreciation in order to turn a profit?

Put 20% down (if $120k he puts down $24k). Rent for enough to break even. In 30 years he owns the place and only paid $24k for it. That’s a 500% return on investment. Is this too simplistic? If it appreciated during that time there’s icing for the cake.

I’m not a bull and not pushing this idea, just asking. I wouldn’t put all my eggs in this basket either but would include it as part of a diverse portfolio.