It's the free country thing. Typical rental leases renew every year (and typically, renters like that freedom). A landlord can simply decline to renew if you're "too much trouble".

So you could challenge the illegal rent increase in court and win, but then he declines to renew. You could refuse to pay the illegal increase (doing it the right/legal way) and/or even just stop paying rent. But then he eventually evicts you, or just declines to renew.

In the end, rent is supposed to be temporary. And when it is temporary enough that moving out can be your leverage, it works. If you are settling down somewhere, it really should be owned.