I realize this isn't the case for everyone, and I realize my situation was odd, but... there's always a trump card: you can drop out. I get that for international students it's not always so simple (losing your student visa, having to go home) and can be a very hard choice.

My supervisor and my department occasionally tried to push for things that I believed were ridiculous, and the threat of dropping out seemed to work reasonably well to push back on that. My understanding is that a supervisor having a low completion rate is a black mark that can hurt them, especially if they're chasing tenure. I didn't pull this out like a petulant child stomping their feet when they didn't like their chores, but rather when things were getting stupid.

Tony: "This is totally unreasonable and the timeline doesn't work for me."

Supervisor: "This is how it must be. There's no other option."

Tony: "I could drop out and continue on with my life."

Supervisor: "Now wait a minute, let's see what we can do to make this work..."