It could still address bubbles in a small way, by making them more accessible: if you can switch the overlay easily, you can get a peek at what other people see

It could still address bubbles in a small way, by making them more accessible: if you can switch the overlay easily, you can get a peek at what other people see and understand their point of view a little better. You can also see what your favorite overlay is censoring and decide whether you're okay with that. Also, one avenue to radicalization is a feeling that your views are being censored. If you get to choose your bubble, that argument is undermined, so extreme bubbles might have a harder time growing.