lethal-cuddles:

I don’t think we can really define Spongebob as Classic Spongebob and Modern Spongebob anymore. I would argue that there are now three distinct eras of the show.

First, we have the Classic Era. Starting with the first season, up until the release of the 2004 movie. These were the seasons produced while Stephen Hillenburg (RIP) was the showrunner. After production on the movie was wrapped up, Hillenburg stepped down and most of the original production team left to work on other projects.

This brings us to the second era, formerly called Modern Spongebob, a more appropriate name for this era now would be the Seasonal Rot Era. Starting with Season 4, most of the production staff was replaced, and the writing took a steady decline in quality. While the show still had it’s share of good episodes, the number of bad or mediocre episodes increased. The most notable complaint was flanderization; the personality traits of all of the main characters were exaggerated into caricatures of what they once were. Season 9 was the last season produced during this era, which brings us to the current era of the show.

Stephen Hillenburg and some of the original writers returned for the second Spongebob movie Sponge Out Of Water, and rejoined the production staff partway through Season 9. The writing started improving again, the flanderization from earlier seasons was slowly undone, and we started getting episodes that were either almost as good, if not on parr, with Classic episodes. This is what Modern Spongebob refers to now. It’s not quite the same as the classic seasons, but it’s also an improvement over the post-movie seasons.