If USD stable coins become a generally accepted form of payment, it won't be long before Bitcoin does too.
Bitcoin can be quickly swapped for sats & vice versa.
A vendor can receive either & quickly swap it for their preferred SoV.
The reason they like USD is because it holds its value better & is more widely accepted than their local currency. They're comfortable with tether because they're comfortable with USD.
From there it won't take them too long to become comfortable with holding Bitcoin.