> I’ve even heard of people being told they need to be “at their desks at 9am” and “expected to stay until 5pm at a minimum.”

PMs always manage to end their day on time with "I'm heading out for a bit, I'll be back online later tonight for a quick check in on progress so send me a link when the ticket is complete" and I'll be able to finally say without guilt or shame "I'm heading out too and I'll continue working on your ticket tomorrow from 9am."