Suppose I've got a search engine. It's the best there is for searches in politics, sports, health, education, shopping, entertainment, and nearly everything else.

Country X passes a law that says search engines cannot return politics results.

If I stay in country X and filter out politics then the people in country X end up with no politics search and the best search in the world in all the other categories.

If I decide to not operate in X then the people there use some second rate search engine that obeys X's law. The people of X still end up with no politics search and they end up with second rate search in all the other categories.

How does my not operating in X help the people of X?

The people can live without your search engine, because there are other ways to find content.

It's hard enough to mount resistance against a repressive regime when it is blanketed with propaganda.

When companies like Google and Apple operate in those nations, they help legitimize and normalize that regime, confirming all the propaganda.

After all, the Google brand didn't come from the regime, they are a foreign firm that decided it was ethical to do business there.

If no one operates in X, X feels pressure to either compete themselves with subpar service as you have said, or they lose out on revenue by opening up for free trade and no longer restricting access on search engines to politics.

If you are asking how best to help their population in general, there are a lot better things you could do to help their people out. At a minimum, you could start your own private search business that refuses to limit your searches and fill in a niche and make an even better search algorithm rather than dictate what you think a private business should be able to do with their platform.

If this were a public right or utility, then you have an argument maybe, but last time I checked, private businesses aren't in the business of serving a public right, only try to make a profit.