I'll do you one better. The hardest part of making crap people like is the damn people. I have been a product manager for a decade and I can confidently say if I deliver exactly what the customer asks for I would be an utter failure. Requirements and software that fulfill what a customer says they want will ultimately lead to them asking for something they previously didn't realize because it actually turns out they have no idea what they want, have an agenda, or the conditions have shifted from under you and what they said no longer holds water.
I could go on a tirade about this but my two cents is you gotta listen to what everyone says, but assume they are a human at the end of the day. It's too damn easy for me to suck up dev time with what people want. Hell, just one word can keep a dev team busy for a long time. Internationalization! Boo!
I also need to build an environment where the dev team doesn't despise the business due to a history of constantly shifting goalposts, borderline abusive metrics, and expectations that just create a battered development team. For some reason hiring a PM aligns with an org hitting the point where the original dev team has lost critical members because of terrible burnout and a culture of blaming people and not process. Takes a lot of therapeutic communication to remedy that.
TLDR; People. People are the reason all things are difficult.