Don't worry, it's not just you: https://lkml.org/lkml/2019/8/4/15

It's because linux is a toy OS. Specifically, it overcommits memory in the hope/assumption that it won't all be used at once, but doesn't have a way to gracefully degrade when applications collectively want to use more memory(+swap) than it actually has. You can turn off overcommit, but applications are designed with the overcommitting feature in mind, so your experience might not be as good as you were hoping for.

Making a massive swap space helps a little bit. It's better to just never let your actual memory usage go above 85% to 90%. It's fine to go above if you're trying to optimize a server with a specific set of processes to wring every last bit of efficiency out of it, but not for general desktop computing.

If it really bothers you OpenBSD (edit: thanks for the reminder TimTheTinker) and Illumos don't allow overcommit at all and Windows handles this situation much more gracefully, so WSL is an option too. If you don't mind Oracle (i do), solaris also doesn't allow overcommit.