You’re both kinda right — yes GP’s evaluation was (probably) why the Elon transaction happened, and also it would not have
had to happen if the owners were a handful of private individuals who didn’t mind passing up a majorly overvalued offer like that.
Of course, anyone at all who cares about money would have been a fool not to force him to buy it once he screwed up by bluffing in a way that made him contractually obligated to execute the transaction! So in practice, since even super-rich people love getting more money and non-rich people really want to become rich, good luck in practice spinning a hypothetical where Twitter owners would have said no, especially considering what a dog the company was already in terms of making money.