Why am I not getting shortlisted for Amazon

I see so many vacancies at Amazon and I've applied to a lot of them with an ATS optimised resume to align my skills and experience with the JD. Last year in Oct I received an email for completing an online Hirevue assessment with 4 rounds. After that, I've also not received any other online assessments for the roles I've applied to or received any call for interview. I don't know what more I can do or where exactly I am lacking. I also applied to most of these roles via referral but I'm not sure what is the reason for not getting shortlisted

P.S. It's for non tech roles in brand management