This is a revolutionary concept.
These chips that began life in mint condition became absolutely trashed from day-in day-out casino use, and eventually they found their way into our hands. Now, for the mere cost of very modestly shrinking their diameter, we can restore them to very close to their original condition - clean, colorful, and (almost) sharp-edged. And since they're now in the hands of home-game hosts instead of casinos, they'll keep their newly-restored beautiful condition forever.
Numismatic purists would consider this sort of alteration sacrilege. But coin collectors have a very different aesthetic than we playable set maniacs. The way I see it, the chips were damaged by their use, and what we are doing here is healing them. If they must give up a bit of their size in the process, then that's merely part of the tragic consequences of having become damaged in the first place. But the fresh lathing repairs the damage, compensates for it as best as possible, and brings the chips back to their intended appearance so that they can resume their original function and return to their original purpose - as attractive and functional objects, art and utility hand in hand.