I don't think this is quite correct.
The online world has echo chambers that protect egos.
In the real world, you don't get to choose all the people you're surrounded with. It's possible but you have to go out of your way; it's not just something a few clicks away.
If you believe in wrong, deranged shit, and speak about it, you will be embarrassed in the world pretty soon. Online you can just find a forum where everybody else speaks the same narratives.
Another thing that protects ego is online is not seeing who is blocking you. As well, the practice of shadow banning goes out of its way to avoid bruising egos, so that the targets do not abandon their account and create a new one.
In a mixed form where subject faces plenty of this agreement but disagreement also, they will tend to downplay the disagreement. A few people agreeing with a subject goes a long way towards erasing embarrassment.
The United States now has leaders now who got to their positions by not caring what comes out of their mouth or keyboard online. This observation, with a conscious or unconscious, emboldens people not to be embarrassed.
Just intuitively speaking from decades of online experience, I cannot agree with the general idea that people are more careful with how they behave online due to fear of embarrassment. I mean people say things they would never say to someone's face, let alone with others watching.
There are some online people who care about matters of correctness who would be deeply embarrassed by being factually wrong, sure. But a good many of them don't care about the tone they use in their interactions.