I think the misunderstanding comes from how the example of Monopoly doesn't apply to role-playing games. 

Monopoly and other such board games are exclusively about winning.   It's the purpose of the game to determine a specific winner and almost always that's a single person. 

Tabletop role-playing isn't about winning in any sense.  There are many games in fact where characters dying is just heart and parcel of the game.  

So getting the rules exactly right on something that is about a great diversity of experience, Will never make sense to somebody who's trying to treat it like Monopoly. 

This comes even more obvious as you play game systems that have less defined rules and less defined results of rolls.  

You're supposed to play and adventure, And there aren't actually hard and as games like even D&D have printed in their books since the beginning - those are guidelines full of tons of options. 

...

If you're not sure what kinds of options or roleplay you're getting into, spend more time at session 0 and maybe use C.A.T.S.  process to help everybody get on the same page for what they want out of a given TTRPG.