What's your biggest gripes regarding war mechanics in EU4?

For me, it's the fact that you have to siege so much land just to get a small fraction of what you sieged. I understand that being able to fully annex a country in a single war would be broken. But I feel like sieging land should both be harder but more rewarding. I think CK3 is a good example of sieging/war score done right, say you declare war for a duchy, all you really need to do is siege the specific duchy you want and win a few battles, not march to your opponent's capital and destroy their army just for one duchy. I think out of everything I'm looking forward to how EU5 handles war and warscore the most.