My previous employer (which I also joined as a startup) ended up in a situation where the head product manager became VP of engineering (it's a complicated story - don't ask). We also had a yes-man director of Eng and together they went all-in on very orthodox scrum, where they sat in the sprint planning/point meeting and overrode every decision of what to take off the backlog and enforcing "themes" of each sprint to ensure that only product work got done. It was very rare that any tech-debt work got dealt with, and security work was only done if it burned down CVEs or other "quantifiable" metrics that were contractually obligated.
I ended up ok as there was eventually an exit, but the core experienced engineering team all left within 6 months.
Now I'm not only allowed, but encouraged to take initiative and while of course I do product work, I can also take a step back before taking two steps forward again.
"Yes we want you to build a faster-than-light spaceship. Your energy budget is this candle."
Why do we give managerial control to insane people?
do you mean "unorthodox"? What you describe sounds both terrible and not very scrum-like, at least ideally (I too have experienced when whatever terrible approach you use is labelled "agile" by leadership...)
What's worse is that I kept getting written up because my main role was DevOps, which meant I was highly interrupt driven...which isn't something you can point reliably.
A decade of consulting had me always ready to wrap my engagement at the end of any day, and (for better and worse) I carried this with me to future jobs. I always miss (at least some of) the people, but never the situation when it turns sour and I leave. The good news: you often get a chance to work with the good ones again (even if that's because you entice them away to your next gig).
^1 https://archive.org/details/ifthisisntnicewh0000vonn/mode/2u...