So why don't we look at the problems with the "sex industry"? Racism? Wealth inequality?

TRAs always talk about being 'intersectional' and then go on to ignore the intersecting factors.

They only care about intersectionality when that means pandering to men and including them in women's spaces. Attempting an actual intersectional analysis might lead them to conclusions that don't fit their narrative, so it's best to avoid it.