Not a terrible film. But not in league with the first 3.

Rating: 7/10 (23 June 2019)

Although I think this film is overall about a 7/10. Which is ok. I'd give Cars a 7/10 and Brave probably a 6/10. Let alone cars 2 or 3.
However, I really despise Pixar deciding to make Toy Story 4 given that the other 3 movies are 10/10 or maybe a 9/10 in the case of the first one. But the original Toy Story gets brownie points for being first feature length animated movie and first Pixar film. The decision to green-light this script is a 1 or 2 out of 10 decision if you ask me. Because it had the complete opposite effect of Toy Story 2 and 3. Real fans and legacies are built on quality rather than quantity.
The Toy Story films as a duo and trilogy seemed special because they escaped the typical sequel problem of going downhill or being redundant. (Which is especially common for kid-friendly movies)
Toy Story 2 and 3 were such good sequels because they didn't just seem to keep the original vision going, but also improve on, or build on the strengths of the previous films.
Toy Story 2 has the Emily flashback sequence. Toy Story 3 has the Lotso backstory plus the poignant moment where Andy passes on his toys to Bonnie.
Toy Story 4 has an emotional moment or two. But it doesn't have the strong central plot of the other films.
It took me long time to figure out what #4 specifically was lacking after I watched it, but luckily I found someone with the answer. Which is that the film doesn't seem to clearly be about one big storyline in the action packed dramatic 3rd act, like what we see in the other films.
What feels like the craziest most dramatic action sequence in the first 3 films is the middle of the 3rd act. (It's called the climax for a reason)
In Toy Story 4 what feels like the most dramatic moment is in the middle. Which is when they try and and fail to rescue Forky.
Meanwhile, the end of the middle act, where in the first 3 pictures, the main characters learn something important and make an important pivotal decision, is instead, in Toy Story 4, placed at the very end of the 3rd act. And it just didn't feel fresh in a good way. Instead it felt a inferior, unclear and insufficient because the viewer isn't sure what the characters are fighting for in what should be the climax. And if feels it can't work as a climax yet because you're not sure yet what they're all fighting to achieve. This issue alone easily drops the film at least 2 stars.
I also objected a bit to some slow-paced moments in the beginning of the film.
The film doesn't seem to have a villain. Obviously it's good to have red herrings for the audience trying to find a villains. But generally you want there to be someone or some characteristic which is a clear source of the conflict for the protagonists. I don't know what or who that was in this film.
Buzz following his buttons when deciding what to do seemed contrived and like a step backward rather than forward for his character.
The end credits were also noticeably awkward. Why all the pauses to show credits between the clip sequences? Did anyone honestly think this new style was an improvement over the style of the end credits for Toy Story 2 or 3?
The strength of the film was the new and returning Bo had many funny and heartfelt moments. The score and voice acting were still top notch. Bo peep in particular was neat to see and hear once more. (Can you believe that it has been 20 years since we last heard Bo speak?) The look of the film was mostly very enjoyable too.
Some people were annoyed that characters like Rex, Jessie and Mr Potatohead weren't featured much. But I feel that would have made the story seem even clunkier and even harder to follow than it already was. If you stretch the viewer's attention to too many characters in a movie then there's no interesting or cogent story to be had with any of them.