Hence the concept of the golden age, renaissance and whatever we are in now. Most of those movies just were not well received. The marketing push for Pocahontas outstripped Lion King and then it simply fell flat on its face. The lull between Jungle Book in 67 -> Mermaid in 89 was just the same, Disney basically ignores the majority of those movies for good reason.
One other one I forgot that really should be added to the marketing love affair is Stitch, sort of the equivalent to Pooh in a sense, which also randomly came out in the middle of the lull.
Even if marketing doesn't love them, the 19 years between Lion King and Frozen certainly had some worthy content. Hercules, Mulan, PaTF and Tarzan were certainly all at least 'good'. I'm somewhat partial to Emperor's New Groove, but that's a
very ignored movie.
Reviews seem to match marketing pretty closely, except for Emperor's New Groove:
https://www.rottentomatoes.com/guides/best_disney_animated_movies/#