If you believe that, then it doesn't seem like you understand the basic concept of checks and balances very well. The fact that checks and balances can be perverted and subverted and are imperfect doesn't imply they are completely ineffective and irrelevant. The fact that the FBI is fighting in court for the ability to command Apple to hack the iPhone is a perfect example of this. "The government" wants to force Apple. O..K... "the government" isn't going to let "the government" do that. This is a useful way to talk about things to you?

"When it comes to the powers of "government institutions", it seldom makes a difference that only "parts" of the government believe/do what is being discussed."

You point out an example where "checks and balances" somehow reigned in the FBI from decrypting a phone. While at the same time, hundreds of other acts have occurred that were not stopped by either public-outcry, private institution defiance or a "check" by another portion of the government. The point I was making is that when a government entity decides to do something towards a private individual, more often than not, other parts of the government don't have a say (at first definitely not, arguably still not long after the fact). To back that, you could use countless examples of every single failing part of government, or an injustice caused by it.

To say otherwise, I believe, is to try detract from the actual implications and make them seem more benign and less dangerous

That's your point. And I think it's a bit silly. Saying "the FBI wants to break into the iPhone" instead of "the government wants to break into the iPhone" is just more precise. It doesn't imply there's any less of a problem. The fact that you have other parts of the government to appeal to, and which may disagree with the first part of the government, is important! If you're involved it gives you a hint as to how you might proceed. It tells us which parts of the government we might have to restrict or promote.

What, pray tell, is the advantage of thinking of all these different and differing institutions as one monolithic entity, or of calling them "the government" as if they were?

Calling it "The Government" exaggerates the strength of the forces for or against something. It becomes a dystopian 1984-esque war.

When instead it is described as "some strategists at the FBI", or even, "some of the upper-brass at the FBI and DOJ" it becomes clearer that this isn't a problem that a revolution will have to solve. We could probably handle it with everyday boring old politicking.

That's like saying it makes sense to say that all Muslims are terrorists just because 1 in 4 Muslims believe terrorism is justifiable. XD [https://en.wikipedia.org/wiki/Muslim_attitudes_towards_terro...]