It is NOT a 1:1 indicator of either a tire's 'stickiness', nor how long it will last, but
generally it holds somewhat true (there are SO MANY variables which go into those two disparate traits, but the one seeming 'physics defier' tire is the Michelin Pilot Super Sport/4S, which sticks as well, or better than, as most 200 tread wear donuts, but wears like a 500 tread wear all season, but is BIG $$$$, and NOT available in sizes we can use
).
To make it even MORE confusing, the manufacturers are NOT required to test their tires against a DOT/NHSTA STANDARD test tire for the
tread wear ratings (like they are for the "ABC" rated, braking/wet braking tests).
In most cases they just test against their OWN brand other tires in their lineup, or whatever they want.
There are also 400+ tread wear tires which burn up much quicker than that rating would belie, and 200 tread wear rated stickies which shock their owners with how long they last.
Add to that the few autocross super glue deals (like the RE71R) which are stamped 200 tread wear for
rules meeting purposes ONLY, but grip more like an 80-100 tread wear rated road race type 'velcro stick' tire, and do not get 'greasy' even when very hot.
(NOT sure
how they wear on the street, you would have to ask some of their owners/users on here.)