I've said it before, I'll say it again:I think it would depend on what your definition of "social media" is.
For a long time, I've felt that a large part of the problem is that we went from a state where the norm for internet discussions was to have everything divided up by topic (i.e. forums), to a state where the norm was to get a "feed" of what was essentially the stream of consciousness of other users.
The problem with the feed system is that it's damn near impossible to filter out the content you don't want (because it's only separated by user-designated hashtags and there's no moderation), and it reinforces this idea that nothing is off-topic or irrelevant. The fact that the majority of internet discussion now happens on a handful of websites owned by mega corporations who only care about pandering to advertisers, and the fact that smartphones and apps have made it so easy that a chimpanzee could participate and so ubiquitous that you can do it whilst taking a dump, is just the icing on the cake.
I honestly think that if we could go back to the system where you had to have some basic technical knowledge to participate in the internet, and discussion happened on smaller user-run forums, it wouldn't be nearly as bad. Unfortunately, it seems that a lot of people actually like the internet version of babbling to nobody in particular on a busy street corner, because it makes them feel important when people glance their way or stop to argue with them. They'd never give it up.
Anyway, I think @White Devil's right that the Zoomers and late Millenials wouldn't know what to do with themselves, but most people who remember the time before would be able to cope. They'd probably be more upset about the inconvenience than anything else.
But your sum-up is way better.