All of you need to remember one thing. World Cup matches are never played in empty stadiums. The demand for tickets are 10 times or 20 times the actual supply. During the 2022 World Cup, Qataris reserved a large fraction of tickets to themselves and made massive profits by selling these tickets to fans at exorbitant prices. So the argument that fans from the host nation may not watch the tournament in case their team is not there doesn't stand. If they don't watch, then fans from other countries will be ready to purchase the tickets. IMO, host nations should not be provided with automatic qualification. They need to qualify through the qualifier tournaments, just like the other teams.
Because this is a big tournament, there is never a doubt that there will be not fewer fans and that is also one of the reasons for FIFA to increase the number of participants because it means more money will be circulating throughout the World Cup. Conditions like any of the hosts will not reduce the interest of spectators to come directly to the stadium and watch the match even though there is a possibility that the match will be boring.
If regulations appear, the host country will not automatically become a participant because they still pass the qualifications. There may be less interest from the country that organizes it, because apart from economic reasons, one of the reasons why countries are interested in becoming an organizer is because they get the privilege of their national team automatically playing, and the rules of the organizing country automatically playing out like a lucrative deal for FIFA and that country.
The amount of money that is earned by everyone via World Cup is crazy. The hosts make money, Fifa makes a lot of money, the hotels around it makes money, the events around it make money, the shops around it makes money, players make more money due to endorsements as well, hell even clubs make more money because their players worth more if they play well, and even go as far as say that national teams that are not the host make money by selling their jersey as well, that merch income is not something small.
So, overall if we look at every single cent earned thanks to world cup, it is a 11 maybe 12 digit amount, I bet 30-40 billion at least when you calculate it all, and that's not easy to do that is a huge amount of money we are talking about, unheard of in anything else in the world.