After passing the exam, is it really a requirement to pay the $50 annual renewal fee in order to receive the certificate?
Yes, you are required to pay a $50/year AMF as well as earn 45 CPE credits during your 3 year certification cycle.
"Maintaining your certification extends beyond passing the exam. It requires earning continuing professional education (CPE) credits that ensure your skills remain current and demonstrates to employers and your peers that you are committed to your ongoing professional development. You must earn 45 CPE credits during the three years of your certification cycle, as well as pay your Annual Maintenance Fee (AMF) of U.S. $50 each year to maintain your certification."
https://www.isc2.org/certifications/cc#Certification%20and%20Membership