It wasn't algorithm, or glitch, or bug. It was a decision made by humans, including you know who. It's a form of crowd control. That's why it's important to have several channels for 'producers'. For others it's a good idea to have several sources. You'll see much more even if each source represents a single side (which is usually the case, 'democracies' are no different).
I can give you a first hand example. One big sh*ty bank didn't let me see my accounts if I refused to activate a debit card. After login they showed a message box, when I pressed 'cancel' they logged me out hoping I will 'click through' to get access. This way they didn't have to explain and could claim it was a bug. It lasted for months till I closed all accounts and they confirmed, but actually didn't do it. What I mean by this is don't expect big company to play nice.
The ML is good enough to know whether your followers want to engage with political content. If they don't, Facebook will show them less of it.
This is a very simplistic explanation. If the GP is a political activist and "always comments on draft laws", I would expect their followers to be willing to engage with political content.
How do you know the reason for your reason for zero reach is any different than mine? I assumed Meta's algo decided none of my friends would be interested in what I posted, not that I was being censored.
They did respond to my next 2 posts so no idea the difference.