My experience since MS started the yearly role-based certs renewal, and this is supported by the FAQs, is that you only have to take the renewal for the certs you want to maintain there is no dependency on other certs remaining active.
Given that SC-300 is a pre-requisite for the Microsoft: Cybersecurity Architect Expert you might want to keep that one renewed in case you are targeting that expert cert in the future.
Generally the effort involved in renewal is minimal and a great way to keep up with the changes.