Oyo's trick seems to be that they're not building hotels themselves (which is obviously slow and very expensive), but they're applying branding & quality control to existing unbranded hotels and taking a hefty cut in exchange for distribution.

There are plenty of budget hotel chains in India (Treebo, Ginger, Lemon Tree, Fab, etc), some of which have been around for 15+ years, so obviously Oyo has done something right to leapfrog all of them.

That's called franchising and I wouldn't call it a trick since many brands, especially restaurant and hotels, have been doing it for a long time.