I don't really see the point in having a phone if you're not going to answer it.
It's like that MN line about invitations to go somewhere: it's an invitation, not a summons. It being a convenient time for someone else to call you doesn't mean it's a convenient time for you. Someone having your number does not mean you have the obligation to be always available to them.
Personally, for me the 'point' in having a phone is twofold: 1) to communicate with a few close family members and friends, and 2) because nowadays it's almost impossible to not have one. You're forced to leave a number practically everywhere and going through things online means you can't just leave it blank, while often it rejects the solution of 000000000000. Lots of things require phone/app verification. I've blocked calls from unsaved numbers and only temporarily unblock if I'm waiting for a med. call (irritatingly, the GP usually, but not always, calls from a number I have saved). I'd be pretty happy without a phone.