Is it possible to stop Craft from logging so much? I've got a Craft CMS installation that is set to production mode. I notice that my logs get flooded with a bunch of entries which don't seem very useful.

For example, in a matter of several days, I've already got console.log up to console.log.5 - So it's rotated the log file 5 times already. These files are filled with what seems like every single query that gets executed on the website. They're 70k lines a piece. It also logs a lot of entries in queue.log, among other files.

How can I stop logging information and only log things which require my attention, such as errors?

Thanks!
As someone who theoretically might inherit your site one day... and also as future-you trying to diagnose a problem... please don't try to limit what Craft logs. If you want a quicker way to look for critical problems, check out the Yii2 Debug Toolbar as discussed here Profiling your Website with Craft CMS 3’s Debug Toolbar
You can use it to very quickly and easily see only errors, or only warnings, and so on. And then if the additional data that Craft logs is needed to help you diagnose a problem, it'll still be there.
To learn how to parse the Craft CMS log files quickly, check out the Zen and the Art of Craft CMS Log File Reading
If you do end up wanting to make your own logger, check out the Creating a Custom Logger for Craft CMS article
I echo Brad's comments, though, unless for some reason devMode is on, it shouldn't be logging every query, except for performance profiling.