Tom Patten’s review published on Letterboxd:
A very large chunk of The Secret Life of Pets 2 is pointless and dumb. The movie focuses on three different sets of characters in three different plots, and two of them are entirely filler. It reaches the credits at around the 80 minute mark and I'd say about 20 minutes of the runtime is the actual plot (Snowball and the Circus Tiger). Worst of all, the main character Max gets the least amount of screentime and his subplot contributes almost nothing aside from hearing Harrison Ford voice an animal. The Cat subplot is just there for stupid gags and contributes nothing as well.
It really felt like three different episodes or short films stitched together to make it feature length and you know what it wouldn't be so bad if it was at least entertaining to watch. Sadly, the jokes are not funny at all and the whole thing is bland and uninspiring. Honestly, for me it made the first Secret Life of Pets seem not too bad in comparison. At least that one had structure and felt like an actual movie even if it wasn't original. The Secret Life of Pets 2 didn't even entertain the kids in my cinema so I consider it a waste of time and easily one of Illumination's worst movies.