In Germany they deployed Annex J where there was no POTS, ISDN was a lot more of a thing there so digital voice.
Crosstalk is as frequency dependent as everything else. The higher the frequency the higher the attenuation.
Having xDSL crosstalking with POTS is bad and crosstalk would, at a raw power level, probably be worse at the receiver at lower frequencies due to lower attenuation between transmitter, a modem, and receiver, your ears. Ever pick up a handset while a dialup call is in progress on the same line?