So, either ICANN could have just maintained a list a forbidden TLDs (especially for those where even the owner doesn't use it) rather than forcing these corpora

So, either ICANN could have just maintained a list a forbidden TLDs (especially for those where even the owner doesn't use it) rather than forcing these corporations to pay for them; or, the money could have been used as a kind of tax on the wealthiest to fund DNS infrastructure and lower the prices of domain names for the rest of us. That clearly didn't happen.