It’s hard for me to overemphasize how how central this is. Like, every day that I program I use this, right? It is one of the key things that keeps me sane. Like, you can make lots of other features of the language away from me but like with my last dying breath I will keep my exhaustiveness checks.
Typing and, especially, exhaustiveness checks are tools for working on any code confidently. They are the vises that allow you to confidently cut in some places and add weight in others. Put effort and rigor into your typing so you can have the type-checker and compiler bear weight for you.