It's not gain as in "what do I gain from it" but gain as "what difference will it make". The solution to the problem has long gone, with the possibility of making the tournament elsewhere, even if it required each group to be based in a different country.
It's a test of character; right now no nation has enough character to refuse to play in stadia or stay in hotels (and new cities) built by slave labour (and dead slave labour at that), refuse to pour thousands into the economy of the nation, and refuse to take part in anything that would promote the vile bastards who run the country.
Character? That sort of decision has to be made by a whole lot of people, and has to take into consideration the ramifications for those who are not at fault about what happened in Qatar. It's not as simples as you may think.
The teams being there is inevitable, but they have the power to protest. Either be it by using obvious nods to certain problems (as it already happens in many leagues with the use of rainbow-coloured braces), or anything else.
There could be (and maybe should) an agreement to make all the profit from the tournament go to those families actually afected by all that. Teams refusing to play, means only that all those lives lost, were for nothing, that will be easily forgetable in a week. Meanwhile, with the event happening, those problems you mentioned, are still talked about, and that probably would not happen if the WC was called off.
Anyone remember when all the players stood up against Russia's homophobia in 2018 to spread awareness and change minds inside the nation? Yeah, me neither.
The problem in Russia is way bigger than homophobia.
Pretty sure that the Qatari broadcasters aren't going to let anyone speak out against the regime (or at least not for very long) and the country's record of refusing to let dissidents and foreigners leave is long and bloody. Nobody is going to "spread awareness" from within the tournament; nobody's brave and stupid enough.
Except that I'm not talking about one random dude protesting amidst the game. I'm actually talking about a collective effort by all parts involved to demand change, from the players, teams, media and all that. Will Qatar arrest or kill everyone? Good luck with that.
The only way to spread awareness is a massive, headline-grabbing cluster**** of one team - or more - just refusing to go and take part in it at all, and doing something else instead, to screw up the event. Which will also rile the homophobes, gynaephobes, transphobes, and racists in their own nations too.
When was the last time something changed when some headline-grabbing cluster**** happened? Has racism in America ended with the death of George Floyd and all the attention it got? No, but we saw the extreme of anti-racism people burning down stores as they protested, which affected others who might not be to blame for anything. Which gave another reason for racist people to stay racist. It also affected people outside the US, as in the weeks after, whenever a black person was arrested for an actual crime, it was labeled as "racism".
How can you stop racism, when you put a racist (anti-white) as one of the main faces of an anti-racism movement (the guy literaly said that "the white man needs to be killed").
If you want to end homophobia/transphobia and so on, why do they keep pushing for heterophobia? Why do they come up with stupid ideas like creating a "financial bonus" for being part of the LGBT... community (proposed in Spain)? Why is a man that doesn't want a trans woman, labeled transphobic for his preferences?
Why is fatphobia a problem when it's against women, and it's fine towards men?
Had to search what gynaephobes were, I assume it's gynophobia, aka, "fear of women"/"fear of being humiliated by women"?
Why do you think feminism is so hated? Is it:
A) because men inherently hate women; or
B) because some of the ideas in that movement are really extreme.
Back on topic, why do we need to propose extreme measures, to try to solve problems like these? It never works, as the more you force people to do something, the more they hate doing it.
And you want to rile up those people you mentioned? Why? To generate more hatred? To make them even more extreme?
The solution to stop any of those problems mentioned, is by people learning to see other people as people, and if anything, everyone stays in their own path, as long as it does not affect others. And this kind of event, broadcasted around the world, can help with that, if done right.
I live in hope, but also the knowledge my hope is misplaced.
Hope in humanity? I never had. People in general care only about themselves and what affects them. And this is for everyone. Even those who do good, in most cases it's for self gratification.