Prior to updating, I encountered wandering traders often in 1.16.5. But after hours of playtime in the new release, I have yet to see a trader show up in any of villages. Gamerule 'doSpawnTraders' has always been set to true and I am not sure whether I'm unlucky or if this is an issue in the new version.
I am able to get traders using the '/summon' command as a workaround but I'm not a fan of using cheats.
Steps to reproduce:
1 - Play in a 1.17 world for 3+ hours and hang around villages
You don't need to be around villages for wandering traders to spawn. They spawn basically in any solid block. Also, this could be normal. The wiki states that, currently, — "On average, it takes 10.411 Minecraft days (or 3.5 real-life hours) for a wandering trader to spawn."