> One fringe punishes any criticism of the establishment view viciously (the epidemiologists & medical experts who weren't for lockdowns comes to mind),

This is rewriting history. At the start of the pandemic the position of "lockdown is a bad idea" was taken very seriously. Only when it failed to provide results and some people still clung to it they got called out. That's literally the opposite of what the article describes (holding on to outdated science, because of "momentum").