The UK hasn’t envisaged needing industrial scale munition production since the Korean War.
Even during the Cold War the expectation was that, if it went hot, it would be a fighting retreat to the Channel using in-place stocks before it went nuclear on day 3 or 4.
Same reason we didn’t have enough manpower to provide guards and shut down SHQ, supply, catering etc to provide them. Hence the shock in GW1 when all the UK units were gutted to provide the drivers, cooks etc to support 24/7 ops for months in the desert. Each 3 Sqn wing MOB providing just enough crews to just keep just one flying 24/7.
Even after that every post that wasn’t “digitised” to show it had a deployable overseas role was civilianised.