Vectoring is available at airports with radar.
Radar is very expensive, not only because the equipment is expensive but also its ongoing operating cost, and the extra higher salary of radar-rated ATCOs. ATC salaries are a huge cost, partly because they are well paid people and partly because you need a suprising number even for daytime coverage.
An airport can purchase a radar service from a nearby radar unit; for example Biggin pays Thames Radar for a radar service. I don't know how much they pay but rumour has it that it is well into 5 digits per year.
No airport is going to pay for radar (one way or another) unless they have the traffic (basically, plenty of light jets as a minimum, and Biggin supports some extremely high net worth client traffic) and the vast majority of GA airports will never have this, so procedural approaches must remain.
And, as that CAA report correctly says, very few planes have approach approved GPS kit. The approval costs the bigger part of a grand, and upwards.
But, using a NON approach approved GPS, you can fly an NDB or VOR approach
This is the silly paradox of navaid approaches. For safety (accuracy etc) you fly them with an IFR GPS but the GPS does not need to be approach approved because you are not officially using it.
Whereas you can fly an NDB approach using an ADF which is half hanging out of the panel and is really useless. Actually, I don't think the ANO even requires the carriage of an ADF for flying NDB approaches! Instead, it requires ADF carriage for all IFR in CAS, which takes care of it for Class A-D airports, but this leaves the question mark over NDB approaches in Class G, where no ADF is mandated. This has always puzzled me, because e.g. Switzerland mandates the carriage of an ADF for flying an NDB approach, which is at least logical. In the UK, you could fly an NDB approach using a tuna sandwich.
Almost no modern pilot flies NDB approaches in particular, using the ADF. How many pilots fly NDB/VOR approaches with the GPS
without even looking at the ADF/CDI I wouldn't like to say; I do use the old stuff as a cross-check at the FAF but that's about it. However, occassionally it is easier to fly SIDs using the navaids (it's a VOR usually) because the GPS database depiction is rubbish... which is why one might use the OBS mode anyway and never use any ex-database overlays.