I assume we’re all paying for this and WHY?
Assume makes an ass of (y)u(o) and me.
As a starting point you need to find out if it is being funded by the Government Project Gigabit scheme. If it is being funded under that scheme then it is correct that the capital costs are being funded from taxation but the end result will be that the ongoing maintenance costs of providing telephony and internet access to each property will be reduced. In global terms this will provide payback of the investment.
If it is not funded from Project Gigabit then your assumption is absolutely wrong. The capital investment is then being undertaken by a private company who will hope to make a return on that investment by selling services to members of the public or by commercial deals. If you do not deal with a company using the services provided by that investment then you have suffered aggravation but it has not cost you a penny.
As a rider to that, please remember that Openreach is a private company and not funded by the government so if you are seeing Openreach vans or contractors it is still not costing you a penny unless you use the services provided by that investment.