I'm not currently streaming using QUOBUZ, but I can attest to AT&T being generally awful. Luckily, AT&T doesn't offer fiber in my area.
I switched to T-Mobile fiber and couldn't be happier. 2 Gig on ethernet and 900 mbps on WIFI. Far better WIFI coverage in my challenging MCM, aluminum clad house. I do stream Hi Rez files on Amazon through the the provided NOKIA server/router without issue. I know I'm not utilizing ultimate quality like QOBUZ or Tidal, but the T-Mobile system is fantastic.

