MacRumors published a tutorial about how to fix high CPU usage caused by Accountsd on Mac.

Accountsd: How to Fix High CPU Usage on Mac

Following the release of macOS Catalina version 10.15.7, an increasing number of users have experienced an issue with a system process named "accountsd" showing very high CPU usage in Activity Monitor, causing their Mac to slow down. One user in the Apple Support Communities shared a screenshot of "accountsd" with CPU usage above 400%, rendering their 2018 MacBook Pro "useless." While this issue has popped up occasionally over the years, there has been a noticeable uptick in complaints across the Apple Support Communities, MacRumors Forums, Twitter, Reddit, Stack Exchange, and elsewhere since the release of macOS Catalina version 10.15.7, with users attempting to troubleshoot the issue. 

Accountsd: How to Fix High CPU Usage on Mac