"No, it's less effort than that"

1975: Fred Brook's wrote[1]:

“The bearing of a child takes nine months, no matter how many women are assigned.”

Can't get better than this

[1] https://en.wikipedia.org/wiki/The_Mythical_Man-Month

I have even smart managers look me in the eye and say things like "can we parallelize parts of this? let's map out the dependencies."

EVERY EXTRA PERSON YOU ADD MAKES IT TAKE LONGER. The fastest delivery is a solo developer that you get out of their f**ing way and let them work.