Were I to guess, I'd say it's probably due to internet speeds in the US taking forever to get up to 1Gbps. There's little reason to push out consumer switches faster than 1Gbps when the inbound internet connection only goes up 100Mbps.
To add a 3rd more minor reason: for the prosumers DACs/fiber is faster, cheaper, and uses less power. The only reason to go to 10GBASE-T is for cases with existing cabling where 2.5G/5G might make a lot more sense if you don't absolutely need 10G. For everything else go 10G/25G passive DAC or fiber.
802.11ax can go >10gbps without needing any fixed infrastructure. 10GBASE-T is basically abandonware now, at least for consumer applications.
For servers, fiber is even more scalable (25/50/100/400G), and about as easy to handle.
Not quite >10 Gbps on 802.11ax though - standards compliant gear has a max theoretical cap of 9.61 Gbps half duplex using 8 spatial streams and 2.4 Gbps half duplex if one end is any current client chip which is limited to 2 spatial streams. Realistic numbers a little lower, I can get ~2 Gbps goodput on an AX210 in the same room as the router on an empty 160 MHz channel. Still far more than any home consumer will need but it's a bit of a ways off of obsoleting wired 10 Gbps full duplex throughput, especially with the cost of 2 8x8 APs.
Xfinity sells 1.2gbps (used to be 1gbps) and 3gbps (used to be 2gbps) to homes, but the upload speeds are horrible. At&t with its fiber offerings just announced 5gbps speeds, but they're very expensive and have horrible practices that prevent you from using anything but their router.
Bell in other parts of Canada is starting to offer XGPON service (up to 10 Gbps) with a unit that has an integrated ONT, so bypass gets trickier.
https://broadbandmap.fcc.gov/#/provider-detail?version=dec20...
The main reason we try to bypass AT&T's router is because their NAT table is capped to accept 2048 entries and starts dropping sessions after it reaches the limit. This is why I stated that the web UI method you mentioned is not a true bypass.
The gist is that you'll have two ethernet ports dedicated to AT&T, one for the ONT, and one for the gateway router (which needs to have the gateway's mac address). The pfSense interfaces have to be setup a specific way. There is also a script that has to run while pfSense boots. Once it boots, you can pretty much turn off the gateway and put it away. The only time you'd need to reconnect it is if your ONT loses power.
I hope that helps.
I'm thinking about using JTAG or something to extract the key, because I'd much prefer having everything handled by my own server.
I'd still be happy to pay AT&T the monthly rental for their modem and for the privilege of leaving me alone :)