I know, you're absolutely right. It was created in 1981 when the RAF was building up to hundreds of Tornado GR.1s and the USAF had 160 F-111s based in the UK. All of these had the capability for automatic terrain-following flight at low level and all of them spent virtually all of their flight time at low level. Even then, R610A was rarely busy. Nowadays we have a tiny fraction of that fleet and a tiny fraction of their flight time is at low level.
Also of interest to note that R610A is the only piece of airspace in Europe where low flying in IMC is permitted. You wonder how Italian and German Tornados managed, since they never used it.
We hear a lot these days about "Flexible Use of Airspace". But it has never been applied to R610A. It could be activated by NOTAM only.
Of course that would mean that, when it's not NOTAMed active, all the military VFRs would pile into the area as well as you GA types......