Some time in the last few years, all of my Google Contacts contacts became “starred,” rendering the feature useless and annoying me constantly. I finally fixed the problem today.
The interface has no obvious method to bulk un-star contacts, and I didn’t find anyone else talking about having this problem. I wasn’t going to manually click to un-star several thousand contacts, especially when it takes a few seconds for the page to refresh upon un-starring, so I wrote a really simple script that can be pasted into the javascript console. I just had to let it run for half the day, but the problem is solved.
setInterval(function(){document.querySelectorAll("*[aria-label='Remove star']")[0].click()}, 5000)
Running this will (eventually) un-star all the contacts on your screen, at least until Google changes their interface.