He certainly did no 'laying of cables'.
I got a phone call at about 8.30 when he told me that he was about to disconnect my phone and would be visiting me shortly. I presume that he was at the nearest outside/street junction box when he made that call, and there would already be fibre optics from the exchange to that box.
He did no work on the copper cable which comes from that street box.
It is the fibre optic length which supplies the speed, and the copper wire length which reduces it. That's why speed can vary between nearby properties. The one with the shortest length of copper gets the best internet speed.
The logistics of your property sound similar to mine
Maybe the fact that there are virgin cables laid in this road has made a difference. I don't know enough about the technical aspects to say anything for definite.