YC is slowly drifting away from its original mission.

I think that they tend to fund people who they think will have the highest chance of success. You end up with priorities like:

1. Previous successes

2. Company with traction

3. Employee at Stripe/Google/Apple/etc

4. Smart MIT/Harvard/Stanford student

5. Misc. high magnitude achievements

I think what you're seeing might be a higher number of 1-3 applying to YC, not leaving much room for 4 and 5. The four and fives who do get accepted are extraordinarily impressive.