How did jio beat vi and airtel?

Though this isn’t related to startups, I’ve always wondered about this, so I’m asking here.

I understand Jio’s free SIM scheme—there wasn’t much competition back then. But when they ended the free scheme, why didn’t Airtel and VI launch a ₹100 plan to regain their market share?

Jio had already spent a lot during those six months, so there wasn’t much they could do—they had already drained their capital. If Airtel and VI had launched a ₹100 plan together for three months, Jio might have had to file for bankruptcy since they had already lost so much money. On the other hand, Airtel and VI, being established companies, didn’t offer a free scheme and could have used their existing capital or taken loans to replicate Jio’s strategy.