I would assume all POS systems have to take a percent cut, given that they clear credit card transactions. They have to at least take 2-3% to cover the cc transaction fee.
Clover's fees are:
Card-present transactions 2.3% + 10¢
Keyed‑in transactions 3.5% + 10¢
So if you have a merchant acct, you'd have to negotiate rates with Clover et al. directly?
If you're a smaller actor, there are POS systems that make their money on your transactions, but even among those Clover is a really bad deal. Compare to Zettle for example, that comes with a POS system, has no monthly costs and a flat 1.75% fee: https://www.zettle.com/gb/pricing