Security through obscurity should be long dead by now. If the only thing stopping people from damaging these assets is their 'secret' location, we have a big problem.
Security through obscurity has different merits depending on the context.
In software, it is a really bad idea to hope that your code is so obscure that no attacker will find a security flaw.
IRL, on the other hand, unknown positions of assets are often critical (the uncertainty whether you know about all the adversary's nuclear silos being a huge part of the nuclear deterrence policy).
There is just so much resources you can throw at discovering underground pipelines.
People like vandals and thieves and vagrants can be deterred by obscurity. There are lots of things which enjoy a modicum of peace and non disturbance because of obscurity. Maintenance sheds, utility rooms, etc.
I did a quick check and RAF Fylingdales is easy to find on Apple and Google maps. However, my OS Maps app won't find it even though I can find other 'normal' RAF bases (e.g. RAF Lossiemouth).
