Why does the size of the work that needs to get done matter? If you need it you need it. If you don't, you don't. If you want a fast fix, note it. Speak in outcomes. "The lowest amount of work possible to get us ________"
> All is us have likely experienced "why is x taking so long??
I wouldn't work with a PM that disrespected me like that.
> Had we known, we wouldn't have done it now!" and/or "we didn't realize y was so simple, otherwise we would have done it months ago and probably won a few more deals!" How do you avoid that?
This isn't prioritization, it's a PM making ill-informed judgements on dev work. Don't have your PMs do that. Product people can define priority, scope, etc. If your PM isn't prioritizing something because they think it takes a long time, they do not understand their role.