If you want Hibernate to work on your Linux laptop, you'll need to have a swap partition with space equal to (or bigger than) your RAM. Apparently, while there is a way to avoid setting aside a partition by using a swap file instead, it doesn't seem to work as well as using a partition.
Hibernate seems to work OK on my current laptop running Linux * and using a swap partition. I've had poorer experiences with previous laptops though. Now that I'm sure it's possible, having functioning "Hibernate" is a requirement for me when buying Linux laptops.
* - A LaptopWithLinux laptop running up-to-date Manjaro.