Petitions are often denied when evidence lacks specificity or fails to demonstrate sustained acclaim. Simply listing achievements without proving their significance within the broader field can lead to a negative final merits determination. USCIS frequently looks for objective documentation of influence, impact, and recognition beyond the applicant’s immediate employer.

Extraordinary ability is the most important thing to prove, so if the applicant can't prove that, the petition will most likely be denied

Things like Insufficient evidence of extraordinary ability, failure to meet the specific criteria, weak evidence, weak recommendation letters