Are people seriously having these dramatic issues with calls? In all my years (as in decades) with all kinds of corded, cordless, early cellular, to current mobile calls I've never had any issues rising to such dramatic levels or even close to them. Sure there have been a few bad connections at times and some dropped calls at times, but generally not many and only here or there. The only real noticeable sound quality issues I have come across on a somewhat more often basis at least more in the past would be some VoIP application calls depending on connection and all that.
That's your experience, it doesn't apply to everyone.
Everyone has a different experience and different problems with that experience.