They ruled that people acting together have all the same rights that they would have acting individually

Bullshit, corporations are not "people acting together", they're autocratic command structures where one or few people hold all the power.

preventing someone from spending money on producing and promoting their speech effectively prevents them from being heard

Also total bullshit, unless you agree that allowing people to be poor is a violation of the first amendment, because being poor effectively prevents them from being heard. Which you won't.

Which are both perfectly true, common-sense statements

I'm already confident you don't have a single ounce of common sense in your empty head after reading those two sentences.