An open source program available on GitHub called TinyNvidiaUpdateChecker is available for those who don't want to use GeForce Experience to grab new drivers. It's tiny and its main advantage is it consumes no system resources because all it does is open, check, download a new driver if available, and then close.
Unfortunately, that's pretty much all it does. If you use TinyNvidiaUpdateChecker in place of GFE, you'll lose all the extra functionality as well as auto notifications for new drivers. You'll have to manually run the program when you read on PC Gamer that there's a new driver. I'm sure we're pretty fast to break news about a new Game Ready driver but not as fast as Nvidia itself. Also, GFE cleans up previous installations when updating and has been doing this since version 3.9.0. TinyNvidiaUpdateChecker does not.
The other caveat is you'll have to check for a new version of TinyNvidiaUpdateChecker if Nvidia decides to update its update-API that GFE uses. For the past part, having a bookmark button your browser taking you to Nvidia's driver page does nearly the same thing.
I can see how those who are OCD about system resources can feel the need to avoid GFE but realistically, CPUs these days have more than enough power.