Set up Einstein Automated Contacts and enable suggestions for Opportunity Contact Roles. Then select the option to improve suggestions.
Here’s how it works: Activities from Salesforce contacts who are part of opportunity contact role suggestions are added to the opportunity’s activity timeline. The more activities on the timeline, the more opportunity contact role suggestions. When users decline suggestions, the related activities are removed from the activity timeline, which improves the relevancy of both activities in the timeline and the suggestions.