A warm welcome to the forums.
What you wrote is true ... but what's your question?
Remember that as with any supplier there are lots of very happy users who never have cause to come to support forums, whilst those that do arrive with some level of dissatisfaction. What concern are you seeking reassurance or caution over?
All ISPs (other than Virgin Media and some specialist cable suppliers) use the same local network infrastructure from the exchange to the premises provided by BT Openreach. If there are faults with the circuit, it matters not which ISP you are with, it will be the same BTOR engineers (or their sub-contractors) who attend and attempt to repair issues.
Thereafter, you are looking at service responsiveness if you have an issue.
Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.