There's one thing to add to it. If they are treating the OP like that, they rely on him being desperate. If they sense that he's trying to get out, they will fire him just to make a statement.

So any drop in productivity must be accompanied by a plausible and pitiable excuse. Like "I can't sleep that well after that car accident" or something similar (but never "I'm burnt out" or "I stopped giving a fuck").

I disagree, business that fire people "to make a statement" don't last. And it seems OP is just good at what he does, hence he will always have more work.

My opinion is that the company likes having OP in a desperate state because in doing so he won't have enough time to look for a job elsewhere.

Oh, that depends. If OP is critical to their business, they normally would not fire him. Except if he sets and example for other employees, so their productivity starts dropping as well. Or if part of the manager's compensation is the right to treat reports like shit and fire them on a whim, as long as stuff gets somewhat done (i.e. a non-asshole manager would ask for more pay). Or if their entire business model is to churn through naive people by using them while they are still productive, and quickly disposing of them as they approach burnout.

I disagree. Some companies just torture people, there is no evil plan behind it.

Some pitable excuse would just paint target on OP's back. Burnout is normal in companies with high churn, they have process to cul weak members... And OP does not have any holidays or health benefits, tough sh*t..

The whole point is to fly under radar, until OP finds new job. Detaching from company politics, staying invisible. Some excuses and more communication push you deeper, in oposite direction.

Also company probably has no real way to measure productivity. People who understands code base left long time ago. Managers are just paper pushers. The only information management has is from OP. Some excuses would be admission of slow down.

Ideally this productivity drop would be spred over several weeks, maybe after major holiday, reorganization or reassignment.

I think they call this quiet quitting

The term quiet quitting sounds like the brain child of some morally deprived reprobate in middle management who wants to abused employees for more than they're being compensated for

I've had this happen early in my career- worked permatemp as a junior and finding out what I'm allowed to do as a 1099, so I decided to set my own hours. Co-founder of the company wasn't happy about it. He hired me as a contractor and didn't like that I established my rules as a contractor. Odd.

Wasn't just me at this workplace, but all the individual contributors were as well. We saw the writing on the wall, that the co-founders were not interested in full-time conversions and turnover rate increased.

It actually made me question the legitimacy of software careers for a while, because I was caught in this illicit operation.