ok hear me out, i watched this movie when i was 12 but as far as i can remember  it's essentially the hero myth for children. It follows a kitchen sponge and a starfish who never wears a shirt as they venture into the dark unknown to retrieve a crown, which serves to protect Neptune (literally god) from being ashamed of his bad genetics so that said god can rise to save Bikini Bottom from a fascist dictator who is mind-controlling people through buckets. 

During this odyssey, our heroes Spongerobert and Patrichard utilize a comical burger car which belongs to Mr. Krabs, owner of a restaurant, which is a good choice as they could claim that saving the city involves saving the Krusty Krab, therefore making their trip is work related, which is preferable tax-wise.

Now, our heroes venture into a world of dark beasts, eventually discovering the figurative dragon of the story, a diver who sells bullshit on the beach to tourists. They find his lair and return the crown, making me cry in one of the best scenes in any move i've ever seen. Upon returning the crown, they find out that the fascist dictator has essentially made god his slave and that god cannot save them anymore. But Spongerobert recalls the lessons he learned while facing the unknown, he overcomes his inferiority complex by accepting that enjoying child-related ice cream treats with clown faces as an adult with a job is weird but also not immoral and also how being tucked between the man-tits of a german athlete made him make peace with his repressed homosexual tendencies, he sings a song about being a "goofy goober" which means being a employed adult that hangs around ice cream places (where children usually are, kinda sus tbh) and plays a guitar solo so epic it end fascism (that's what the Soviets did in 1945 i think). 

The main takeaway of the movie is that by venturing into the dark underbelly of our usually orderly world and by confronting chaos and overcoming one's unconcious fears, one can elevate their mortal flesh to be above god, culminating in Spongerobert saving Neptune from fascism and bringing peace into Bikini Bottom, which btw is a sexual metaphor too deep to be delved into in this here post. 

Also Patrichard is a sigma and Patrichard x Mindy Rule 34 is in fact  official Spongebob canon,  which makes Patrichard heir to  the throne of god king Neptune, which will be interesting to watch as it has implications regarding the ending of the Squidward cock vore storyline.