Did you read their announcement when they banned him[0]? Banning the man representing, at minimum, a quarter of a country with such nakedly partisan logic is an embarrassment to anyone who wants to pretend Twitter cares about liberal political ideals. They were listening to voices in their head rather than reading what Trump wrote; voices which obviously won't tolerate anything outside a narrow, illiberal view.
[0] https://blog.twitter.com/en_us/topics/company/2020/suspensio...
A system that, based on their flimsy justifications, simply bans political opponents isn't liberal. The classic position a liberalist should take is that the service policy needs to be reformed to embody better values around free political speech.
Not that I'm too invested in the situation. Twitter will be on the way out soon enough if it doesn't pull its head in and tolerate serious dissent from the favoured narrative.
And as the president, he had the entire American media apparatus at his disposal. The premise that somehow an American president can't effectively communicate policy without a Twitter account is absurd. Previous presidents have been able to manage just fine.
The US is very, very divided. Trump won with basically 50% support, he lost re-election, and then lost even further support when he started making up lies about election fraud. Even if morality was derived from popularity (or just profitability, if that's what you think Twitter did it for), Trump no longer had close to a majority. Maybe his comments were in line with expectations of 60% of Republicans, but the other 70% of the country thought that was what was unacceptable.
The standard under discussion seems to be free speech absolutism with the question "how much more liberal could twitter get". The ban of Trump just makes a good high profile example of Twitters current limitations on free speech.
The governmental account is still active.
They literally banned the President of USA. Are you seriously asking this question?