Everyone using (the same) social network sites is a common misconception of those who use (those) social network sites.

For example, Facebook popularity in Russia is maybe 1/10th of Instagram popularity in Russia, and Vkontakte is used 5× more that that.

If whatever handful of things are your most used sites/services/etc online were shut down tomorrow would you consider it the end of the internet for you? You'd (I guess, at least I would) immediately move to the next best (maybe even discover it's better!) or wait for a competitor to spring up.

So there's a huge difference between those few platforms blocking Russia but a whole world of alternative ways to spend time online vs. only domestic Russian options.

WeChat is the internet for most people.