Procedural really ought to be taught & be available. However, keeping proficient enough to be able to use it I in a serious situation with lots of traffic is problematical. it was abandoned partly because of the reliability of Radar systems, but also as a cost saving matter. I think that the cost saving element was given far too high a priority & that Procedural training should have continued.
I also have to reflect that when undergoing TRUCE training, ATCOS at my unit, who had no experience of controlling without SSR, were at a complete loss of how to continue Radar Control using PRI only. This is highly regrettable & ought not to be allowed. But, that is the modern way, & every penny counts !