If POTS last mile is available, why complicate it with VoIP?
Because it is cheaper and easier? It is a lot of equipment there simply does not need to be there. If you have DSL you have CPE equipment and that CPE equipment can have FXP out for very little extra. You also save having filters to separate DSL and voice.
In any case, even the ILEC here is dropping analog and delivering phone services via VoIP and FXP out on the CPE. I believe because the technician only needs to go to the DSLAM to connect you. If you are also getting analog voice, he needs to go to the CO too because voice and DSLAM are no longer cohosted.
Regards,
Baldur