THIS, I actually agree with. First Shrek, I'd argue, still holds up in a weird way. Mostly due to the gooey emotional center it has, which is BARELY enough to overpower said pop culture references. Every one after the first one relies on referential humor way too much.
Do they?
I am going to be honest, I can’t remember any reference jokes in either Shrek Forever After or Puss In Boots. Shrek 3 had a few background gags, but nothing hit the level of the Cops or Burger King scenes from Shrek 2.
A lot of the issues of Shrek come from it getting too serious, Puss In Boots being heavily noted as a weirdly straight take on a fairy tale for a Shrek film, and a reliance on gross humor. The heart of the series will still present in 2, 4, Puss, and even parts of 3, but it is very obvious that 3 marks a transition in the series that makes it very different from before. I think the style change between films really destroyed the franchise at large.
The first was a Disney hate thread hiding a genuinely great subversion of Disney fairy tales. A story where the monster of those tales gets a happy ending with a strong message about looks. The second is a continuation on that plot line as now it isn’t building a small community of outcasts, but being accepted by the greater world. Stuff not shown in fairy tale stories like meeting the parents becomes a thing. The main story has the same theme of acceptance, but shows how society creates pressures to be a certain way, hence why Shrek caves and transforms to be fairy tale typical. This is hidden behind a frantic string of jokes though, some references, some crude, and lots of sarcasm.
The third is slower paced and riddled with fart humor and “ha dork” humor. The plot is good conceptually, but poorly executed. There is no longer an acceptance story that can be told with Shrek, so it starts becoming a story about the aftermath. It continues the post-happily ever after plot by introducing kids and the idea that Shrek needs to be a leader now as he is the king, both of which never have challenges explored. The idea of shifting the acceptance message to the villains of fairy tales is also a good idea. Execution got muddied though as Prince Charming is a weak antagonist without his mommy, Arthur and Shrek have a mishandled relationship and there are tons of side plots that go nowhere. This is without mentioning poor jokes and how they ruin impactful scenes like Harold’s death. The plot of Shrek training nerdy Arthur to be a good leader not by pulling out the sword and becoming the usual Chad, then him giving villains happily ever after to deafest them could be a good plot, but that isn’t what happened. Too much in too little time with no real focus. In a sense, make Shrek become a father through Arthur, which I assume was what they were going for.
Shrek 4 is a basic plot executed well. It is an average mid-life crisis leads to It’s a Wonderful Life. Basic, but fits Shrek seeing as he is very different from the start at this point. He is no longer the lonely monster, he is an attraction people love, a husband, a friend, and a dad. The movie makes his relapse to Shrek 1 Shrek pretty believable, then hits hard with the consequences of what that means. The love and care he loses, shown brilliantly by the crying scene after seeing his daughter’s toy. The problem with Shrek 4 is the overall lack of humor, making it off putting to Shrek and Shrek 2 fans.
I like to think of Shrek as the very strong non-fairy tale. It is the story of an ogre who gets his happily ever after and has to fight for it again and again as there is no one and done. He has to go through struggles of the happy ending sidestepped in fairy tales: Leadership, children, relationships. Maybe Shrek was a parody at first, but it evolved into something more. It is not a parody like Enchanted where it just says the thing would be stupid if put in the real world, yet ends like a fairy tale. It takes time to show what life would mean in such a world. Enchanted is a fairy tale put through the lens of life, Shrek is life put through the lense of a fairy tale.