Ironically, Bradbury likes to tell people that Fahrenheit 451 isn't about the thing it was obviously supposed to be about (censorship) because he now wants it to have been a metaphor for cancel culture.
https://www.openculture.com/2017/08/ray-bradbury-reveals-the...
They had cancel culture in the 90s too.
Next comes legalized, then deputized, then militarized...
So he sees it as another form of censorship
It's about more than that - many people have lost their jobs, been de-banked, or even been arrested (especially in countries like the UK and Germany) for expressing their opinion publicly when that opinion was merely (a) what most people in their country believed in the recent past (< 50 years ago), and (b) a politically incorrect opinion.
Few now respect the wisdom of 'should not' even when 'can'