I'm not in an affected country, but from what I can gather from what happened most recently:

Steam changed their pricing policy in relatively poor countries from localized affordable prices to strictly usd equivalent because people in other countries were using vpns to make accounts in those poor countries to get games for what would be pennies for them.

I don't remember which countries were involved in the first place, but in those countries now where they don't make as much money on average, but everything is much cheaper, some steam games can cost the equivalent of a month's salary.

That's why the store isn't viable in those countries anymore.

Edit: Here's a source