Yep you don't save anything using your own hardware anymore, and they impose data caps if you use their modem in pass-through mode and run your own router.

I gave up and just use the Xfinity cable modem/router/access point now. Covers my entire house and even outside deck/patio/driveway. Yes they are probably snooping on my traffic and potentially proxying their "xfinitywifi" through my cable, but I use Firefox DNS over HTTPS so they can't see that, and VPN for work.