Were the services (that were reinstated) reinstated in one big-bang? Or was it a case of links slowly being reintroduced once the companies were privatised?
Also, what (in your opinion) was the biggest "lost" link that wasn't subsequently reintroduced?
It's really hard to say but the re-extension of services across the bridge to Newcastle was done at d-day. Of course, there were many services that existed before Metro that would never come back as the Metro is so much quicker and even with a change, it was much better. It was just the idea of a 25 min direct journey vs. a 35 min two stage journey with a change that was silly with services from some parts of Gateshead.
There's a remnant of the 655/755 between Guiseley and Leeds (route 27), the more recent X52 runs between Otley and Harrogate, but there's now just 1 bus an hour between Bradford and Guiseley (and lots of other places which lost their route(s) to Bradford).
I recall having an animated conversation on this forum about the Bradford to Guiseley corridor with someone who seemed to feel that the reason was largely down to First's ineptitude rather than the impact of trains. It's fair to make First partly culpable but, and wrestling this back on topic, it's all fairly simple.
If you provide a faster, convenient alternative, why would you not expect public transport users to migrate from bus to (light) rail? That switch is much easier than leaving your car on the drive.
It explains much of the decline in bus services in North Manchester, for example, as has been discussed many times that contributes to much of the bus patronage decline cited as a justification for franchising -
please let's not go back to that discussion as to that subject!
However, as we've seen, even BRT schemes like Leigh to Manchester will abstract trade from slow bus to fast bus. However, and this is where there were some silly issues in Tyne & Wear.....
Spending 5 mins on a feeder bus, 5 mins interchange, then a 20 min metro ride into town seems ok
Spending 20 mins on a feeder bus, 5 mins interchange, then 5 mins metro ride just seems ridiculous
----even though the timings are the same.