Hanging wallpaper on a bumpy wall looks worse than paint. A lot worse.
Hanging wallpaper isn’t “hard”, especially if you have two people working on it. But it’s not easy to do a good quaility job of it. You have to plan it out so the patterns match correctly, the seams have to be just so after the glue dries and there is a lot of cutting at the top, bottom and around objects.
Last time I wallpapered the bathroom I called my wife in to have a look after I’d finished. She told me I had to move the light fixture over 3 inches becasue she couldn’t stand it being centered on the sink, it had to be centered on … something else, I still don’t understand. Decide this stuff beforehand.