> If you explain to them that "good enough with the money we've got" will make them more money later, they are usually OK

That's true. Some engineers won't take the "just make it good enough" approach, but I believe most will - otherwise they don't belong in a startup.

I wasn't mentioning the broken communication between PO and devs in this regard though. I have seen teams where the PO were not able to describe what they wanted, what business value they wanted to add to the product, devs had to come up with their own description of feature and sure enough the market didn't care of that.

PO is such a critical position, and such a difficult one to fill. I can count on one hand the companies where I worked who understood that. A PO is not just moving tickets around in JIRA, they are in charge of describing in actionable terms the business value the team is trying to produce.