How many are we?

Passed All Interviews & Passed Engineering Leadership Review - Rejected at Engineering Director Review before offer

Hi all.
I am really suspicious about bias on final stage and curious about "how many are we?".
I passed phone screen, passed virtual onsite with some "yes", some "strong yes" performance, passed engineering leadership phase.
And finally i rejected at last engineering director review level before offer.
But why?
Really how many people are there in my situtation?
I have to understand the context behind this weird thing.
Everyone says that this phase is just a quick review session and generally at this phase the previous decisions are confirmed.
As a result, if the interviews are not enough, then the candidate first talks to the directors? We are putting a lot of efforts. And passing all interviews is no simple endeavor .And someone is here to say a simple NO after all of that.
Really i am sad that there is a bias or something like that (i do not want to mention).
I am waiting for valuable comments, because i am in a really very bad mood.
Best luck for everyone.