Even if India and China have the infrastructure to support the hosting of the world cup or they have the funds for it as long as they never bid themselves forward as organizers, is it possible for FIFA to appoint one? It seems that it is impossible because FIFA only appoints countries that volunteered because it means they have the ability or desire to become the organizer, because it seems that at this time FIFA is no longer considering the development of football from the countries that bidding to be the host, so every country currently has the opportunity to become a host as long as it has the funds and FIFA sees an opportunity to get bigger profits there.
Well, profitability is a big concern if the matches are being scheduled in India. Because the government never makes these events tax-free and it won't be acceptable for the FIFA. And football is not the most popular sport in India, unlike the case with most of the other countries. And given the current political climate, I don't think that the Indian government will take a favorable view of hosting the event in their territory. In case of China, the scenario is more viable. The government is more supportive compared to the one in India.
Maybe hosting the World Cup in India is a very difficult task but if India gets permission from FIFA to host the World Cup then FIFA will benefit financially from this country. Because all kinds of sports are very popular in this country and all kinds of sports are organized in this country on a very large scale.
Football is a very popular game in several Asian countries including India, Bangladesh and Pakistan. The people of this country watch not only the World Cup matches but also all the club level matches. And even when the Hero Super League football tournament is organized in India, a large number of spectators enjoy the tournament. So if India ever gets a chance to host the football world cup tournament then India will take all necessary steps to make the tournament a success.