Rebase is nice if you have very careful code review policies. Otherwise, if you don't have humans carefully reading every merge, it is a huge waste of time.

Rebasing also increases the number of conflicts you will have to resolve. I've seen this 'always rebase' advice over and over in the last few years, it's stupid advice that betrays a lack of understanding about how git works. There is no advantage whatsoever unless you also squash your commits, and even then there is no advantage unless you are submitting to a project with very careful code review practices (Linux kernel, a project that uses the gerrit code review tool, etc).