Unfortunately, if Yankovic is so comparable to Zappa, then one might predict a steep decline in his popularity after his death. While Zappa is still considered a major figure, most of his output has never quite entered the wider rock canon and is not widely listened to today. I get the impression that Zappa is about as niche now as Captain Beefheart.
As for bands being sober role models, I used to think that about Rush, which had a reputation for most of its career as the thinking man’s rock band whose members did not have hard drug problems, tattoos or other unkemptness. But then it gradually became known that in the 1980s the guitarist had a cocaine problem. (And he also began extolling the virtues of ecstasy in interviews which, though arguably a soft drug, might have made some people uneasy.) So, for other clean-looking bands, appearances may be deceptive.
As for bands being sober role models, I used to think that about Rush, which had a reputation for most of its career as the thinking man’s rock band whose members did not have hard drug problems, tattoos or other unkemptness. But then it gradually became known that in the 1980s the guitarist had a cocaine problem. (And he also began extolling the virtues of ecstasy in interviews which, though arguably a soft drug, might have made some people uneasy.) So, for other clean-looking bands, appearances may be deceptive.