VM has a lot of independent legacy infrastructure, which is only quoted as “fibre” as it is capable of fibre speeds. Less than 1% of the network is actually full fibre, & the majority of this is being built by NexFibre in brand new areas that were previously unserved.
If VM has been around for several years this will be legacy HFC network that was only built with a finite capacity. As per the above post, VM has never cabled private roads owing to the complicated wayleave agreements required. They will also not share infrastructure on HFC due to the large diameter coaxial cables used.