So now you know why they don't put telephony capability into tablets - people won't buy both a smartphone and a tablet, but opt for just one of the two.
Amusingly the original Samsung Galaxy 7 released in 2011 (?) did require a phone subscription for their european offering. I kept thinking to myself, now that's a big phone!
Though manufacturers figured out the above - tablets will consistently be data-only devices, so they can sell you another unit just for voice.