It's not practical to put fibre up every glen, but should be ok put it to most cabinets, thus making the speed bit at least something you can discuss.
Anyway, the speed and the end to end quality need to seperated. Even the example provided of video conferencing at 2mb is not true, as this would be two streams of as little as 150 -200 kbps (x2) with with loss and delay characteristics of <1% - the latter is the issue not the bandwidth. Bulk file transfers may need to be overnight, but that will need doing anyway as we need to collectively manage to a peak hour capacity.
If i had a spare £15bn I would donate it to FTTC, but we need to manage the end to end service as each application just needs what it needs and no more.
Mobile Data at 2Mb - if it was 2Mb the quality, as in loss and delay characteristics would not be good enough, we will need to be smarter with local wifi and actually pull fibre through where it is needed to support those communities of 200-300 homes.
Wiggle room is needed to define the service but it is a do-able project - where the speed climbs over time, but the underlying quality is defined in the network planning rules.