Simply put, mixing Third Party Services ( Gmail accounts ) into macOS, they do not alway play well with one another.
If the user naialorlander whats to trouble shoot this issue, suggest disabling the Contact Application to Sync with the Google Service.
Then, restart the computer and Test if " contactsd is still consuming all cpu usage "
Where upon, arrive at your own conclusions.
Otherwise, suggest follow the previous advise and or contact the Developers of this Third Party Service to remedy this issue with Their Services
Apple Develops macOS - the Operating System.
Apple does not Develop their Operating System to work with Third Party Services or Applications
That is the sole Responsibly of the Third Party Developers to make their Software / Services to function on the Operating System it intended to be used on.