Phone vs "High-Speed" Internet Gateway

5G has different flavors... low, mid, and high band.  Higher frequencies can offer more bandwidth, but have shorter range.

This is why a LOT of TMO 5g has been low band since it's introduction.  It runs close to, if not actually crossing into the edge of, the range that cable networks run.  Some 4G has also run close to this frequency range as well in the past.  So much so that both have been shown to cause interference with cable systems when their is missing/compromised shielding of the cable equipment/cables.

Keep in mind that these cable systems cap out at roughly 38.88 mbps per channel under the DOCSYS 3 spec.  While cell can easily offer double the channel width at these frequencies, it is NOT going to lock in super high speed even with the highest quality metrics, as it is heavily restricted by that lower base frequency of the channel.

So the lower band 5g can often be roughly the same or even worse than the 4g bandwidth, depending on various factors in play.

If you are lucky to latch the higher mid band frequency, shorter range 5g on your phone though, it will be substantially higher throughput... because it is likely running at least 2x the frequency, possibly even 2x the channel width of the 4g or low band 5g the modem may be grabbing. (n41 verses n71 can be worlds apart).

Keep in mind also that they prioritize cell phone traffic over home internet, so when utilization reaches a certain point, home users will be more negatively impacted.