Tal of Chooka Media Group explains what's a "404 page" and how you can make it work better!
A 404 is usually a dead-end when you try to reach a link that is broken or missing. It's usually pretty plain and boring.
HOWEVER - you CAN use this page like any other page on your website! Make a nice experience for your users, add some call-to-action, leave the navigation menu or just make them laugh with a nice video :)
What does your 404 look like? post a link or a screenshot :)
Here's our 404: https://www.chookagroup.com/error404
And this is a blog with 15 examples: https://www.wix.com/blog/2019/09/best-404-page-design/