As far as I last checked, yes, still possible in the US.

Stores like Walmart sell the phones and phone cards for prepaid service and all that can be paid with cash which doesn’t require ID.

If nothing else, you can buy a second hand phone off Facebook Marketplace or wherever and get a phone card for cash and neither doesn’t trace back to you either.

Of course this is likely because everywhere we go is covered by cameras so you’re never truly anonymous if someone is determined enough.