> Note that the sum of wage + tips must reach the minimum wage, or else the employer is required to make up the difference.

But tips are also often used as a performance evaluation metric, and falling low enough that the employer has to make it up often leads to termination, so, where this is possible (as it most obviously is where cash tips are involved) its not uncommon for employees to be incentivized to artificially inflate tips.

Eliminating the lower tipped based minimum wage (which, when followed, means that tips actually go to the employer, not the tipped employee, to a point) means that, even where this practice and pressure exists, it doesn’t leas to suppressing wages below the general mininum.