Sometimes lawsuits are like a “4th branch of government”. It forces legal compliance (or at least highly encouraged) so in some ways it’s not that different from the typical role of government. Politically, it can be easier for politicians to let lawsuits do the work for them instead of gaining enemies by going after people (which lawyers get instead). You also hear the media get called “the 4th branch” from time to time.
I've seen a model described in which lawsuits are used to exercise executive power while bypassing the judiciary. I have no opinion on how prevalent this is:
1. An agency would like to make a rule, but that rule would exceed their authority.
2. After some quiet discussion, an NGO which is friendly with the agency sues them for not already enforcing the rule.
3. The agency settles the lawsuit, and the terms of settlement require them to enforce the rule. This bypasses inquiry into whether they're allowed to do so.
If something like this happened, I'd be pretty comfortable describing it as a "4th branch of government" or similar.
I agree, but that's all I could find in a quick search.
Anyway, if you read between the lines and realize that some orgs wouldn't behave normatively, you can imagine some scenarios where the OP could be right.
