Functionality of Recently Used Contacts list

I am using a managed Nextcloud service, so cannot de-activate the ‘Contacts interaction’ app. As a result of this standard activated app, some of my contacts appear in a ‘Recently Used Contacts’ (RUC) list that are read-only.

I am trying to understand the purpose of this functionality? And most of all, why such contacts would be read-only. If some accidental / garbage contacts were used in emails, they end up in the RUC list for eternity. And this doesn’t help to keep my address book tidy.

Thoughts?