An ambitious boss would push everyone and squeeze the last drop (perhaps to meet his own perf metrics). Look at how he “talked down”
to others in the team.

My other “bosses” never mentioned i'm too slow.

Changing to another boss may really help you feel far better. Another team may have a similar workload but the pressue and feeling
may be very different. In XR's last assignment, workload wasn't that high, but timelines and boss's demand created a lot of stress.