Found somewhere. Author unknown

Junior dev here. Finishing a boot camp, actively going through a few job application processes.
One of the companies has given me a tech assignment (for a Graduate Junior position, mind you) that was titled Full Stack Mid Level Challenge. It took me a week to build an app they asked and do analitycs and refactoring of the second part of the task (I only had late evenings free to dedicate to that), it was my first time doing back-end in Node (my boot camp teaches PHP) so I basically learned to do it while doing this challenge.
They asked testing and clean architecture.
I submitted the assignment (I thought I would die while doing it, exhausted, I think I was brain dead for a short perio of time, but I submitted it on time).
They got back to me and we had already have a tech interview with the Leads that had live coding at the end. Don't have feedback yet, really won't be surprised for whatever comes, it was literarly my first interview, treating it like a valuable learning experience.

But. This rant is not about this. Thsi is just to put you in my mood.

This is the !rant:

My classmate from the bootcamp is probably already hired, or will be one of these days. As a tech challenge she was asked to do FizzBuzz kata. I repeat, FizzBuzz bloody kata!
Now, I am very happy for this person, the situation is complicated and this job is extremely needed.

But, please, explain to me, HOW??? How is it possible that selection criterias vary that much?

End of rant. Thank you very much.