Employees could collude too, saying "we refuse to work for anything less than X$". Except that employees would do the same thing that employers do all the time

Employees could collude too, saying "we refuse to work for anything less than X$". Except that employees would do the same thing that employers do all the time and walk across the line as soon as someone offers them a compelling deal, even if it isn't at the "collusion" price.