CARVANA interview questions

This is the company I spent most time to prepare for. I went through HR screening- hiring manager- take home assignment - super day consisting of 3 interviews. The interviews are cheerful. The HR is super helpful and responds very timely. I can sense the good working culture. I waited for about 10 days and then was told that they chose another candidate. I appreciate the detailed feedback. But I feel the interview process could have fewer rounds, 3 could already be enough.

Recruiter Call - Take Home Assignment - 1st HM - 2nd HM - Panel (back-to-back with directors). Communication is strong, heard back from the recruiters the next day after each round. Thought I did well in every round and got positive feedback from the recruiter as well, but still ended up getting rejected a week after the final round. I think it probably has something to do with H1B sponsorship, even though the job description states explicitly that the position is eligible for sponsorship.