The 145 very much still has VTs on it, it was the AX/EV types that were replaced primarily by GTs but also SGs. The GTs came from the 11, and the SGs came from the 7, with the 11 now a mix of AX/EV and the 7 mainly EV operated with some AV/AX. As far as I'm aware actually it didn't lose any VTs at all, and if so only one or two.

The 46A/145 are two of the most popular routes, and it's rare to see them not doing well at any time of the day. Bunching however is the one factor that changes this, but 15/20 to be empty is an unusually high number.

I never understood why Broadstone got so many VTs to be honest.. Phibs or Donnybrook could be doing with them more, although some 25/66X/67X services do need them in the evening.