Why are convenience store clerks on the phone?

Serious, unimportant question:

Why are convenience store clerks always on the phone?

I don’t know anyone who uses a phone as a phone on a regular basis. People try like hell to avoid talking to people on their devices, opting instead for text messages, WhatsApp, Snapchat, Signal, Telegram, and even Facebook Messenger.

But it seems like every time I walk into a convenience store, the clerk is speaking on the phone. I know they are often working alone for long periods of time, but when I am alone for long periods of time, I never think to call a friend.

Why would I do such a terrible thing to someone?

These convenience store conversations never slow down my transactions or bother me at all. I’m not complaining.

I just don’t get it.