Question about old vs. recent job postings

Hi!

I have a question for those of you who have some experience working at Mercor.
I joined a month ago and have submitted applications to six jobs (mostly generalist writing and bilingual stuff). Three of my applications have been rejected (approximately one week after submitting or even earlier); the other three are still waiting for a response. One thing I've noticed is that in the three that are still pending I figure as 'early applicant', while in the others I didn't.

I'm wondering if there's some cut-off date for these job postings (like 3 days, or 1 week, or 10 days old) after which is not even worth applying? I am asking this because some of the assessments I've taken for these rejected applications were long (and I mean really LOOOOONG) to complete. It is a bit frustrating spending so much time on them and not knowing if the application was rejected due to quality issues or simply because nobody got to read it.

Any info from experienced workers (specially if you have applied to these kinds of jobs) is much appreciated!