I did originally, when it collected a bunch of obscure knowledge and made it searchable and useful. It was fun and rewarding to put things you knew into the common knowledge pool, and everyone celebrated a successful competitor to Experts Exchange. The SO model had a few major flaws that became impossible to ignore after it was entrenched. First, the reward scheme rewards the exact opposite of what it should incentivise: common questions are hit by many users and therefore attract lots of upvotes while answering the really hard stuff often meant you didn't even get your answer marked as "accepted" (because the OP had given up and stopped checking the site). Second, the site deliberately cultivated an "editor caste" in the Wikipedia style before the failure modes of that model were well-known: well-intentioned newbies get shut down by miserable yet untouchable people who play (and sometimes help write) the site's rules. Third, the stated desire to identify canonical answers to questions had no clear way to handle the evolution of the software people were talking about. So you'd have highly upvoted answers that might have been referencing deprecated libraries, and it was very hard for the newer answer to gain traction via either internal or external search.

It was also unfortunately before the retro boom of the 2020s, so questions about older arcana were often vulnerable to being closed instead of answered.