Big Q fan here! Q sometimes seems more akin to the Norse legend of Loki, a chaotic neutral figure who would sometimes do good and sometimes do bad. Often with a lesson for Picard (esp. season 2 onward but there was plenty of room for character growth, and Q spoonfeeding too much exposition to the audience in his first story would be counterproductive. Plus, with Q, never take 'im at face value and that's part of the fun!)
See my sig line for a link to Q, but here's another good'un:
https://www.inverse.com/culture/star-trek-the-next-generation-35-anniversary.
Roddenberry had to do something to meet the TNG premiere's newly-made edict for being 2 hours. He created, as bookends, the trial, featuring Q and using inspiration from Trelane (much to the chagrin of others, despite Q not having nuclear family parents and a more complex undercurrent!) - this definitely made the premiere more interesting, and John DeLancie's casting was nothing less than inspired. (He even had a scene in "Q Who" changed, to say "Oh please" instead of ranting to Picard in the conference room. Like Michael Dorn for Worf, DeLancie took a character outline and made far more out of it.

)
The sig link is this:
https://stealthoptional.com/article/5-reasons-q-is-one-of-the-greatest-star-trek-characters
It's amazing. Q was in 8 TV TNG stories and 0 TNG movies but feels like he's been there longer or even integral.
My username is in homage to Q as well, "
Qonundrum".