This really isn't an insurmountable problem, twitter just needs to have a way of not letting you cut yourself off completely to the outside world. Show you tweets from people outside your bubble - something it's already created for advertising.
Warning labels also work as a useful reality check.
In fact, twitter was doing pretty well with all demographics except the American alt-right, which is why they fled to Parler and Truth Social etc, which itself was excellent for twitter as it made it a more advertising friendly platform.