If I parent has "the final say" on all issues, that means all the parent's mistakes are final. They aren't going to be corrected.
Parents often speak of "taking into account" the child's ideas, and then making the final decision in a fair way. What this means is that the parent alters his decision exactly as much as he considers right, and if the child considers that wrong, that's too bad, and if the parent is mistaken that's too bad as well.
I do not advocate replacing the rule of the parent by the rule of the child. I advocate that all disagreements be resolved in such a way that everyone genuinely agrees at the end. Until that happens, they must be considered open questions.
One benefit of this is that it does a child a lot more good to learn why something is best instead of having a misconception about it but following some orders. If the child just follows orders without understanding that isn't educating the child.
Another benefit is that it raises the bar for the quality of ideas the parent needs. Everyone makes mistakes, and this will help the parent make fewer. The bar in a conventional household is: whenever the parents feels upset, feels certain, or finds further questions hard to answer (and therefore frustrating), then he ends the discussion and tells the child he needs to stop the sass and listen.
In fact, some of those situations seem to hint that maybe the parent is wrong. (That doesn't mean the child is right. Often they are both wrong, and some other idea is right.)
Having to persuade the child means having to think about how to explain the issue in an understandable and compelling way. It's OK if the parent wants to take a break as long as he comes back to it later. A real discussion also means answering the child's questions. That helps the child learn; any parent should be happy to answer questions. And for the parent, there are two possibilities. Either answering is easy, so it won't be any trouble. Or answering is hard, which means the parent didn't know the answer well enough, and it's good that he thinks about the issue a bit more.