If you do the same for Facebook it's all users no longer using Facebook rather than employees no longer working there
That's because Facebook is a network and you leave networks. Google is a set of services and you quit services.
Meanwhile when you stop using Google products... no one notices. No one cares. It's a completely personal decision. I stopped using Google products one by one when I found competitors I liked better and absolutely no one knows and no one asks because no one cares. I can still email Gmail users and they'll never know. I can send someone an address that I got from Apple Maps and they can open it in Google Maps just fine. If they send me a Google Maps link, I can open it in Google Maps because I don't need an account and a profile and a friends list first. I can use Bing or DDG and no one notices.
It's a really big deal to stop using Facebook. It's a really big deal to stop working at Google. In both cases you're losing some part of your social identity. Not the case when you're stopping using Google products.