Exactly. Square was the first great checkout system, but now a decade and a half later every other system is good enough that retailers aren't going to pay extra for a flashier app.
It’s not extra and their hardware is still far better than the competition. Square is still awesome in the small business PoS space. Their lead has not shrunk.
And before people like my barber would have had a square reader. With NFC in modern phones, they just use that