No, the worst thing is to have your position relentlessly pounded for days by HE and
not have a bunker.
One of the problems for post-oops artillery is going to be spotting. A battery needs someone with eyes on the target, and with fuel being scarce and communications devices no longer being manufactured, the number of ways to do that becomes limited. That's a role that ultralights might do well in, although they'd be hideously vulnerable to any surviving ZSUs or similar AAA systems.