Pretty much 100% agreed amongst the community.
Rebels are tedious.
Wars are fun.
I think this is the one case where everyone agrees, yeah. Even though I love the new rebel system, I was kind of disappointed that the rebel faction design from CK2 wasn't ported over to EU4. (CK2 rebels basically up and leave with a chunk of your holdings that you get back when they are defeated, sort of like a mix of pretender rebels and nationalists in EU4.) Rebels lack agency and strategy almost entirely, to the point that if they're too large to beat right now, you can always just follow them around and siege whatever they just finished sieging and wait for recovery.
To be fair, it would've been hard to implement in EU4, though, due to countries having regular costs that are closely balanced against their territorial holdings, so a rebellion might mean disbanding 1/2 your army, and then catastrophic failure, etc.
But... surely the CK2 rebel faction mechanism only makes sense in a feudal country, right?
I found the old system of whack-a-mole with random rebel stacks annoying and pointless, but the current system (where rebels rise up much less often, but in serious numbers when they do) is much more engaging.
I think I would quite like it if rebellions happened like they do in CKII, so they should form their own country and are immediatly at war with you.
I think I would quite like it if rebellions happened like they do in CKII, so they should form their own country and are immediatly at war with you. Regardless of size you should always be able to retake all the land if you win, if they win they enforce their demands so defection to another country, flip religion (but rejoin your country) etc. In the case of nationalist rebels they should be able to invite the country they wish to defect to into the war, religious rebels should be able to invite neighbouring true faith nations into the war. Because the rebellion would effectively be an offensive war on the part of the rebellion their war goal would be to seize your capital. In order to make this happen though rebellions would need to be much less frequent and progress much slower. They would start with x units spawning but by being their own country would be able to create more units. Obviously there would be far more details to iron out but I think this would be fun.