SAR has been done for many years with what kit was available, whether in a Whirlwind without a second engine, NVG or FLIR and the ability to just about lift the skin off a rice pudding or a Sea King with all sorts of kit and masses of power - but what cannot be denied is that as the technology has improved, so has the capability and the safety.
How many posters here are actually in current front line RAF SAR and know what the capabilities of the Mk3 and 3A are - not what they might have been 5 or 10 years ago.
Unless you have used our FLIR/MSS - you won't know what a leap in technology it is over the MCA kit - it may have taken 20 years to get it but it was worth the wait.
Regardless of who ends up running UKSAR, there can't afford to be a reduction in capability - neither the MCA or the govt will sanction that, so one way or another either the military will still be involved or the civvy SAR will have to raise their game.