Part of what made the original Toy Story movie so fun, and his character having a sense of depth, was that Buzz came to the realisation that he was just a toy, with no backstory, and that everything he thought he knew about himself was just fabricated as part of the marketing to sell many other toys of him.
This is my issue with the new Lightyear movie, that it basically walks around the origin of Buzz Lightyear. It doesn't come across as a Pixar movie at all because it makes no sense rewriting the origin story when that was already done in Toy Story!
To make it worse, subsequent Toy Story movies blur it even further by having many other versions of himself appear, each with their own orthogonal history of their being.
Whatever John Lasseter brought to the company seems to be completely gone.