I don't have to be there, and my dollars don't go to these corps. I don't understand your point.
I'm not on either of those platforms, so they're not shipping me ads. I do what I can to be private, so that their data mining doesn't get me.
I have that choice. Unfortunately if I don't agree with what my government is doing, they'll still take my tax dollars and fight forever wars with them.
Basically it doesn't matter if you support them because most speech happens on those platforms and you are suppressed from there. Sure you can go elsewhere, but that doesn't work when you need to reach out to others.
You don't have to support.
The government will take your support at gunpoint. This is the crux of the issue.