Earlier quoted context omitted.
Technically with moves like this, we already are. The question should instead be phrased: would enough users opt into giving money instead of being advertised to, and that's much trickier. You'd lose some opportunity cost with an ad or not model and having to support that, but I think a nontrivial amount of people would rather spend money than be advertised to.
Eventually paying users will get ads too.
I genuinely don't think it is hyperbole to consider online advertising perhaps the single most destructive invention in the last decade and a half. Many of the terrible aspects of social media would not exist if people were paying for it with their dollars. Social media has exasperated divides and now poses a serious risk to democratic institutions.
Anonymous trolls in a no advertising world would be fewer because people would actually have to pay for those twitter accounts. Moreover, there would be no incentive for online publications to feed us clickbait, sponsored news, and outrage simply to encourage more eyeballs on ads.
While WSJ comments can be pretty partisan and terrible, they pale in comparison to Twitter's.