It really says something about the quality of "The Good Place" that the weakest season is still far superior than some shows' entire runs. However, when looking at every year of episodes back-to-back-to-back, it's clear fans don't have as much fondness for the third season. That's not to say there aren't a few gems among the bunch. When you look at the ratings on IMDb, Season 3 has some of the highest rated episodes of the entire series with "Jeremy Bearimy" and "Janet(s)" receiving a ton of praise.
But, as a whole, Season 3 had more dips than any other season. When you look at the 10 lowest-rated episodes of "The Good Place" on IMDb, Season 3 takes up four of those slots (via Screen Rant). One likely explanation for this would be the vast change in scenery; Season 2 ends with Michael (Ted Danson) and Janet (D'Arcy Carden) sending the four main humans back to Earth after they have been dead for the previous two seasons. Several episodes proceed with the four reuniting, but without much interaction from Michael, who's guiding them along supernaturally (for the most part) from the other side. Not only does it retread territory we've seen before with Eleanor and Chidi falling in love all over again, but it splits up the central cast, meaning there are fewer personalities in the mix.
Naturally, everything goes back to normal with the main cast getting back together once the four return to the afterlife. At the very least, Season 3 of "The Good Place" isn't a slog to get through as there are still plenty of fantastic jokes and wonderful character development. Season 3 also gives us this incredible moment of Chidi adding Peeps to chili, so it can't have been all bad.