Lee was also doing LOTR at the same time.

I suppose one could say that Lee was in a slight career slump in the 80's and 90s as a lot of roles he got were in B-movies (Howling II, the Rob Brown Captain America, Police Academy 7) or ones that were played for laughs at his other roles (Gremlins II), but I think working with Jackson and Burton really restored him to star status.