It still needs to do nearly everything that the "monstrosity" does:
- routing/PPPoE
- ethernet uplink (for fibre ONT)
- ADSL/VDSL modem (for copper lines after WLR withdrawal)
- POTS ATA
- and/or DECT for cordless handsets
The only things it can drop are wifi and the LAN ports.
Given that (a) almost nobody buys a phone line without broadband these days, and (b) the device can be hidden away out of sight, I don't see any need for making a custom smaller version of the box. For that matter, a larger box will probably benefit from better ventilation.
So if it doesn't need Ethernet ports, that can make it smaller and as for ventilation if all it is only doing low traffic, which, then it really doesn't need so much ventilation, in fact it can have a lower powered chip in.
you know why they are doing it, because they think these people will decide to go get broadband and it maybe cheaper to use the same hardware than produce a different type.
You may be right, there may not be that many people who just have a phone and no broadband these days, but there are some. Not many people use dial up, but until last year I knew off two households, now I just know of one, the other one have gone for mobile broadband.
Adrian
Desktop machine Ryzen powered with windows something or other.
Plusnet FTTC