>Im Gegensatz zu anderen FTTH Angeboten, die auf Layer-2 Plattformen von städtischen Werken basieren, benutzt Fiber7 eine komplett eigene Internet-Infrastruktur. (https://www.fiber7.ch/fiber7-verfugbarkeit/)

I think you misread that he misread that. It translates to this:

"Contrary to other fiber-to-the-home offers, which are based on Layer-2 platforms by the municipal works, fiber7 uses an infrastructure all its own.".

That strongly implies they use different fibers.