It is technically impossible to make Bitcoin the main means of payment in a country with a population of over 1 billion people. As far as I remember, the Bitcoin architecture allows for no more than 400,000 transactions per day. This limitation simply does not allow Bitcoin to be made an official means of payment in China or India.
In addition, what about runes and ordinals, which can unexpectedly increase transaction fees not even several times, but by orders of magnitude?
China and India are interested in protecting their national currencies, and they are also planning to introduce CBDC.
Bitcoin may become an integral part of the gold and foreign exchange reserves of these countries, but it is unlikely to become an official means of payment in India and China (in my opinion, this is an unlikely event).
Using bitcoin as a legal tender doesn’t mean it will be the main means of payment because this two countries can never have anything other than their own currency as such it will be used as an alternative currency to their traditional currency. So even if they legalize it today that simply doesn’t translate to its usage by the citizens, the over 1 billion citizen won’t be making daily transactions on bitcoin like you put it out, as there are going to be those who will but even use it, those that will use it will actually limit its usage to transactions that favours them in terms of fees to be paid like cross boarder transactions.
Its impact is simple any adoption growth leads to demand and in turn demand leads to increase in price. So onboarding close 3 billion people is definitely a bullish news that will pump the market