SpaceX apparently doesn't like to give definitive numbers (perhaps there are too many configurable tradeoffs and/or dynamic adjustments to variable environmental conditions for that to make sense), but the downlink throughput of a Starlink V1 satellite is reportedly about 20 Gbps over an area of several square miles. Putting that on a single fiber wavelength is mature enough to be firmly in SOHO/homelab territory these days (e.g. QNAP and Mikrotik both have 25Gbps switches that are about $1000). It looks like commodity CWDM mux/demux boxes can cram 16 of those into a single fiber. It's safe to assume that the big guys like Comcast and CenturyLink/Lumen can get equipment capable of far more than that.