Pretty scary they associate accounts like that.
I know some web developers that have to login to client's Google accounts... For example, using Gmail to download/send mail via their hosting account. Convenience to have it all in one place but some clients who are small business owners don't really want to or know how to deal with things like setting up their email putting in the IMAP and POP details.
Then if you make apps for example, if the company isn't a tech startup you'd be the one uploading the app too. Say they are a small restaurant chain and you wrote them an app.
Also there's local seo companies where companies will manage small businesses Google Business page listings for them too.
There was a story posted about an entire company that got their GSuite banned, and employee's personal accounts unrelated to work got deleted too. https://www.reddit.com/r/tifu/comments/8kvias/tifu_by_gettin...
I like many other people use Google services daily, and a fan of some of their products. However support seems like a blackhole from many other stories online, other's that made it to HN too.
Not sure I'd want to use them for anything business related (Domains, Hosting, Internet, Phone, etc), other than publishing to the Play Store if I ever made an app since you are kinda forced to if you want a popular app that's cross platform. I forget the post but a few days ago people on HN was talking about Google's Cloud offerings and recommended not using any cloud specific APIs. I haven't really been following Google's cloud offerings but I know AWS offers a lot of APIs for databases, etc - but the idea is to use tools and programs that can run on any cloud so it's easy to switch if you wanted or needed too without being locked in. Good general advice no matter who the provider is though.
Google Fi interests me but I remember on the top page of HN someone had a billing problem, and not sure if that was solved. https://news.ycombinator.com/item?id=18886804
Google Fi is supposed to be really useful for people who travel internationally for example, with iPhone support recently added but visual voicemail, etc isn't supported yet... If they add visual voicemail in the future I'd be more interested in switching but support is a concern for me.
Also YouTube other people talk about, don't have that as your only income stream is one of the points. However if you are popular enough I've heard you get like some sort of account manager assigned to you, so maybe they get higher priority for support issues.