What if India or China declares bitcoin as legal tender in the country ? What impact will it have on the bitcoin prices and other crypto coins ?
That's going to be helpful for the people of those countries as they will be allowed to send and receive payments with Bitcoin and that might impact the value of Bitcoin in good way. But, there's chance that making it a legal tender in such populated nations Bitcoin might see huge number of transactions on daily basis and thus there's chance to see way higher levels of network congestion then and fee might get higher.
As it was said, not all would be using BTC to pay for anything, however, it would spike up the fees greatly, in my opinion.
And affect the chain in many ways, positive at that, I would say.