Even the "Bad" bluth films are excellent. Rock a doodle do is a solid 8.5+/10 and I straight up think critics who leave that film with a bad rating are deluded.
Porco Rosso literally reuses music, animations, etc from his other films. I enjoyed the film because a fascist pig cassanova was a fascinating premise - but it's very much derivative.
I bench them against one another because my partner is obsessed with Miyazaki and finds Bluth films to be mundane in comparison. Miyazaki has far more cultural capital today than bluth - which is absurd since more Americans grew up watching the land before time than they did watching anything Miyazaki made.
Earthsea was directed by another Miyazaki, namely Hayao's son Goro.
I love Secret of NIMH, All Dogs Go To Heaven, etc. but let's not whitewash over history. He also did "A Troll in Central Park".
For every mediocre movie like Earthsea, there's also fantastic movies like Porco Rosso, Spirited Away, Naussica, etc - all of which I watched as a "kid".
They both had their highs and lows. Seems rather pointless to try and bench them against each other.