DTI was the holy grail. To get rid of FS, us punters had to be made to believe that ATC could do the FS job as well as their normal job because the new kit was so good.....didn't quite turn out that way
The best way was evolution...instead of super AFIZ verbal diahoria the powers that be should have shared the kit. TAAATS has a virtual track function that was never utilised in low level airspace. ATC could have kept their turf. FSOs could have rerated to enroute yet remain FSOs...may have come in handy for TIBA alleviation...moved to BN and ML looked after the same turf.
The big plus that was never looked at. If FSOs activated GA VFR flightplans within TAAATS would activate a virtual track....back to DTI...IFR is still FPR...back then, that is. IFR track is updated. VFR track just keeps on plowing on unhindered unless there is about to be a conflict. FSO contacts the particular VFR for a position update and next ETA...reports IFR traffic to VFR, updates virtual track of VFR and then can report traffic to the IFR and OFFER VECTORS if required.
I still firmly believe this whole affair was a demarcation dispute. Thirty years wasted. Evolution from ATC/FS through to ADS-B. VFR could have kept dumb as long as they submitted a plan and reported any amendments and maintained a listening watch on area frequency. IFR would have received DTI and ATC could have kept to class C....well...I can dream of what might have been if someone had a bit more of a thought about what was really needed.