Cats is very much a product of its time.
When it first 'scampered' into the Winter Garden, people had never seen anything like it and thus the magic of the sets, costumes and choreography made it a hit. It paved the way for the Brittish mega-musicals such as Phantom and Les Miserables which, like them or not, saved Broadway in the 1980's. New York continues to thrive on $$ from tourists wanting Phantom merchandise, so whether or not you like the non-plot of it, Cats was and will continue to be a piece of theatrical history.
And please, at least Webber and Elliot did their non-plot with class. Look at Brooklyn or a certain other Twyla Tharp musical neither of which contain a plausable plot and yet are currently running on Broadway.
*BTW..I happened to enjoy that Twyla Tharp musical before people start bashing.
"Y'all have a GRAND day now"