If you reject the idea that people are intelligent enough to think about politics for themselves then you reject the idea that they're intelligent enough to govern themselves. Democracy and free speech are intrinsically linked.
Question: Why is this a threat to democracy, but previous censorship wasn't? There's always been an expectation of truthfulness in communication: We don't allow people to go around claiming that Pepsi causes AIDS, or cures cancer. You're not allowed to claim you're collecting for a charity, and then keep all the money for yourself. I doubt you'd be terribly okay with me claiming that you're a murderer and asking how…
But more importantly, I don't even think your charity example works. Like you can be charged with fraud if you just put the money into your bank account, but if you collect for a charity and charge a 75% collecting and handling fee? Are you then collecting to a charity?
In this case it is more that somebody claims you are not collecting for the charity, you show the bank statements that conclusively prove (according to yourself) that you were collecting to a charity. Then somebody starts looking into it and claims they have evidence that you play golf with the bank teller. And that their manager is your college buddy.
And now you try to suppress the (alleged) photos.
To be clear, I don't think there was widespread fraud or voter suppression in favor of Biden. But the key difference is that normally there are disinterested parties (in particular courts) that can rule on the evidence, in politics there are by definition no disinterested parties in the US. And because of the superpower status of the US, it is even worse outside it.