I do not agree with you about the factors and comparing Qatar with America, we know getting a visa to enter the USA is more complicated, especially for people from some countries with a bad reputation and bad relations with the USA but I think America will make an exception and some special rules for the people who come to visit this country for watching the worth cup games. That's why I don't think if there will be a problem with getting a visa.
As I mentioned in one of my previous posts, USA is one of those countries which favor illegal immigrants over legal immigrants. If you apply for a legal visa, you need to wait for 3-4 years to get a hearing. An easier route is to travel to Mexico and then jump the fence over Mexico-US border. Every year millions of illegal immigrants take this step. Now I don't know whether the Americans will ease visa rules for the FIFA World Cup of 2026. If they don't do so, then I don't expect a large attendance from third world nations such as India and Indonesia.
That sounds easy but actually, it's not because it is too dangerous for the people to do that thing. I know that there will be some people who will resort to that option just to see the games in the upcoming World Cup but I don't think that the US is not aware of this and it is already safe to assume that they will be pouring some of their resources including the presence of their military to watch over their borders to avoid illegal immigrants from crossing especially the terrorists who acts and disguised just like a regular immigrant.
The only safest thing to do is to follow the process and execute a tourist visa if you came from a Third World country as that will just take a couple of months to have an interview, having some relatives living in the US is a plus as that will improve your chances. Most importantly, if you're looking forward to see the games, I suggest that you act towards the matter as soon as possible.