I have a 3-year old, and he loves the Paw Patrol. When it comes to children's cartoons there are very few I can tolerate watching myself, but Paw Patrol isn't the worst.
As you say the themes are largely positive, there's a decent range of characters and locations, and usually he's happy to watch an episode a day.
But I do admit I find myself wondering far too much about the backstories! Where does all the technology come from? Who is Ryder? Is he a mad scientist? How did the Mayor get elected? Why does the other Mayor, of Foggy-Bottom, never actually spend time in his own town? And finally at what point (I guess I missed this episode) did the evil-cats become mirrors of the Paw Patrol?
(Also: Sea Patrol? What a crazy and impractial dock for the boat!)
Maybe I should take it less seriously.