[Someone]

That’s because the traditional physical bell needs a high voltage (relative to the digital circuits in modern hardware).

https://www.epanorama.net/circuits/telephone_ringer.html:

”The voltage at the subscribers end depends upon loop length and number of ringers attached to the line; it could be between 40 and 150 Volts.”

I think they also (relatively to the hardware in a VoIP adapter) need a large amount of power.

So, to ring that bell, you need to transform your 5V/3V/…, and you need a larger power circuit. That isn’t worth it for the few who still have an old-style telephone.

[kragen]

I think you need the high voltage anyway, even for a fake bell. The power is probably the problem.