I remember the campaigns slightly more than the ones in H3 that I barely touched, because there was an edgy necromancer hero with a whole campaign around him that I thought was cool

My opinion on it otherwise is more or less the same as yours. It didn't "look right" to me and I found the soundtrack to be a little bombastic, but I also remember liking the approaches they made with magic and the interactions with heroes mechanically. It felt like a similar leap from StarCraft and WC2 into the proto-moba "lane" of WC3

I'd love to see another strategy RPG work off of the game they were experimenting with in Heroes 4. Songs of Conquest does a lot to recapture the charm of 3, and that's great but I feel like there's potential for a different kind of experience with the example of 4