Like they did for Alberto Moreno?
Bad players with no upside don't sell. If they're on good money because you misjudged their ability or potential then they definitely don't sell.
Liverpool aren't necessarily better at the selling part than Sanllehi, that remains to be seen, where they have been much better than Arsenal in the past few years is buying players with at least some upside and then using that evaluation of said potential to decide what to pay them per week.
