Toxicity follows the crowd. The Fediverse seems less toxic because it has a fraction of the user activity compared to big tech platforms. The problem is not in the platform, it is in the users themselves.
I think the fediverse has a more organic way of dealing with this - defederating bad actors is effective and also allows them to continue to exist in their own bubble. In the long term folks can just exist in the pocket of fedi they enjoy all while following and interactive with government and other accounts.