The Core Web Vitals and Page Experience updates occurred this past summer (of 2021), and since then, many businesses and webmasters have taken efforts to try to adjust their websites to Google’s latest direction.
The participant you’ll see in the video below, is also acting accordingly.
She said to John,
“I had a 50% drop in--like, at the end of June, the beginning of July--in traffic. So I know there was a big update then. I think it was Core Web Vitals at that point.’
To this, John Mueller replied:
“Yeah. I think we launched the page experience Core Web Vitals update from June onwards. But I don't think you would see a 50% drop in traffic.
“That seems too extreme for just the speed and the Page Experience update. From my point of view, I would assume that there are other issues that are kind of stronger issues there.”
As with most other updates, some traffic may have fluctuated. But, Core Web Vitals, alone, can’t account for a 50% drop in traffic.
Source: Google Search Central