Why carry a wallet and a phone with you if you only need the phone?
On the other hand, why carry a phone when all you *need* is your wallet? And a wallet doesn't have potential battery or reception problems, etc... Seriously, a phone is not really a necessity.
Also, mobile payments further intrude on one's privacy and can be more time consuming that cash or a CC - for example, yesterday it took one guy (and the clerk) 2 minutes to get the scanner to read the qrcode on his smartphone so he could pay for his lunch. I can see many potential problems with digital IDs as well.
Yes, I realize that my usage and preferences are simply mine. And, sure, I have a cell phone (a Qualcomm QCP 1900 from 1998) but I only carry it when I travel and can't even remember the last time I turned on it.