At a practical level, one of the most important things we can do if we really believe in Western society is simply live it and let other people be exposed to it. Time and time again, simply living well is infectious and does more to undermine totalitarian regimes than pretty much anything else. Most people (on any side of an issue) really want the same thing -- to live a nice life. Fighting stems from different visions of how to do that (or an inability to do that because of poverty, oppression, etc), but in a competition between ideals, the winner is generally the one that lets people live "better".
So as a method of protest, I'd argue it's a complete failure: it removes our most powerful tools, which are primarily exposure based, while leaving a power vacuum behind and getting virtually nothing in return.
The flow of culture from sharing messaging platforms is simply too powerful a tool to abandon as mere "protest".
The existence of the WWW is known. The existence of sites such as Medium or Snap are known. If those exist, but are blocked either by the Saudi regime, or with very clear "this content has been censored at the request of your government" then the abject political control is revealed.
Power often is most effective where it can act covertly. Forcing the hand, or even showing it, can weaken it.
I believe that this is significantly more powerful than the other thing, precisely because revealing a failure of providing a standard of living is more motivational than revealing the use of power in a regime like Saudi Arabia.
"Everyone knows the government filters X, but who cares, we can just use Y!" vs "Why do Americans all seem to have Z, but we don't?"
Though this raises the question of how, across multiple cultures, regimes, and times since the early 20th century, government censorship has been perceived.
My understanding is that Pravda and Isvestia were poorly regarded in the Soviet Union. The old joke: "There is no information in Izvestia, there is no truth in Pravda".
Elsewhere? More recently?
by who's standards?
I think the company's complaints have to seem reasonable to the populace and for there to be no credible alternative. Uber and Lyft pulled out of Austin for a year in the hope that would put pressure in lawmakers to change the rules, but instead local competitors who were willing to deal with the new regulations setup shop and Uber and Lyft both returned.
I don't think Medium or Snap are important enough to have any leverage anywhere.