There is something to be said for the reliability of POTS.
I've had DSL services problems twice where in the evenings, my data rate dropped to zero--unusable.
Apparentyly, DSLAMS can get old and when the do, they slow down during peak service times (evenings). The solution both times was to move li copper pair to another DSLAM port. The first time was before DSLExtreme and the old ISP ws clueless. I spent weeks dealing with them and finally called a press contact I had a Verizon. It then took a few days to get fixed. On the seond time (with DSLx), I knew the priblem. They had it fixed the next day. That's why I stay with them.
I'm still a believer in a pair of twisted copper wires back to a for-real central office in spite of having cell service as well. We had a tornado in our neighborhood a few years ago, fortunately, our house was spared major damage, but the infrastructure did not fare well......except for the phone service. It never hiccuped even though our electricity was out for a full week and cable/Internet was out for 10 days. Cell service was very unreliable as the nearby towers were damaged. I'll keep my POTS line.
Landlines were designed for five nines reliablity, i.e. up 99.999% of the time. Cell phones can't even come close to that, at least not yet. For that reason, I'll keep my land line thank you. If I need to dial '911' I want the call to go through.
Another advantage to a land line is higher availability during a power failure. Just make sure that you have at least one hard-wired phone in the house to supplement your cordless phones.
Don't forget options such as Google Voice (if you trust Google; there are similar non-Google services). For example, you could give out your GV number to everyone, set up call screening, and then have it ring your cell phone. The call screening (and GV's filters) should keep spam calls very low.
MeasurementBlues - I'm still hanging on to a land line as sort of a backup for the house, and to send all of the junk calls too. I suspect it would be cheaper, though, for me to cancel the land line and add one of my older cell phones to my account, and use it for the home.