Once you convert Fiat to crypto, its easier to spend than using a debit/credit card.
Getting it from Fiat to crypto is the hard part. After that you literally scan a QR code or type in an email.
Its my preferred way of paying because I always have my phone but I dont always keep my wallet in my pocket. I dont need to add my address and birth date. I just send money.
Also, to clarify, I'm not a fan of alt coins(at the moment) only Bitcoin I believe is useful. Between coinbase Email, Shift card, and the usual on-chain txns, Ive basically made the change to Bitcoin lifestyle.
The vast majority of people would find it burdensome to convert their money to another currency, and then use that on a normal basis. Of course if you ignore the hardest part, it's "easy".
There are so many options at this point that I never get why anyone makes this about crypto currency. Most of these options are older and more widespread than Bitcoin as well.