You can get a fair way down that path with ansible if you are very careful but it still requires too much work, modern operating systems and packaging where not

You can get a fair way down that path with ansible if you are very careful but it still requires too much work, modern operating systems and packaging where not built for idempotent rollbacks. We try to treat pets like cattle then wonder why they bite us (to reverse the usual refrain). I agree though, it should be declarative but everything shits everything else all over the filesystem.