I have not had a land line for years. A landline is almost useless for me because everyone has their smartphone with their own number.
And even without a smartphone plan, you can make phone calls to someone else using apps like wechat or whatsapp, as long as you have Wifi. This brings me to my next point. Wifi and reliable internet is a necessity.
I actually went without TV service for the longest time as well. Until Bell offered me a combo with TV & internet that made internet cheaper. I'm not really using the bundled TV at all, but it still works out to be a net discount.