I never had to wait 30 secs for an undo in my scenes, therefor I cant speak for others. Until there are improvements, there are work arounds in Blender like scene linking, collections, local view, groups, instancing, bounding box view, enabling only necessary modifiers, baking textures etc, you name it.
I am old school and I personally like scene/asset challanges, if you think I am trolling about it you are wrong. However like I said, it would be nice to have undo improvements. Until then bitching about it here is no help, and your only option is to start thinkering about work arounds.