Has SpongeBob SquarePants reallly declined in quality after its third season?

Many fans claimed that the quality of the Spongebob shows a decline after season 3. This does not mean that it is a fact but each has their opinions and observations. It seems that the decline started when the creator of Spongebob, Stephen Hillenburg, left the show. The team that he left might not have the same humor as he has when writing the previous episodes. And those were the ones that the audience knew and loved.

Maybe the viewers noticed the change of comic and humor that is why they think that the show declined. And the style of the new writers exaggerated the traits of the characters that made the characters looked stupid. Whether new writers or not, Spongebob does still have fans all over the world.