When you first meet him, he gives off more of a young, wild puppy vibe but, just after, the character is meant to be introverted and dignified. His behavior/interpretation become fair and realistic. In a book, we would have long sequences of introspection where we would describe his dilemmas, fears, etc. In a video game, on the other hand, it's auditory and visual. The authors failed to come up with narrative tricks to force Wyll to reveal himself to the player (being surprised by TAV when he doesn't think he's being watched, being too drunk to control himself, meeting a childhood friend, a spell...)
Personally, I don't think always being perfectly realistic in terms of interpretation is a good thing. We lose too much of the emotional connection to fully attach ourselves to the character. The character of Wyll takes too few risks at all levels. Probably an effect of last-minute rewriting.
The strength of the BG3 characters is that you can want some of them as friends (outside of romance) and feel like it's mutual. But without his romance, Wyll remains too distant for me to think that of him. He just remains good company to me. We can't blame him for anything, but I don't get too attached to him either.
