When Google announces that a feature is rolling out to everyone, it should probably follow that up with a huge asterisk and footprint to clarify that it doesn't mean everyone, everyone, just most people, minus a few exceptions, and some more exceptions, and even more exceptions. That's the case with Google One, the company's unified cloud storage solution that was said to be available to "everyone in the US" more than two weeks ago. Not so surprisingly, a lot of users haven't received it yet because of multiple reasons, the most important of which is their promotional Drive storage.

So to sum it up in concise words, Google One is available to:

Existing paid Drive users with US billing consumer Google accounts (with Argentina, Australia, Brazil, and Mexico to follow in the next weeks)

New subscribers with US billing consumer Google accounts (those four countries to follow)

However, there are many exceptions to this. So far, we know that Google One is currently not available for:

Accounts with promotional storage, whether that was received by activating a Chromebook or by completing the Security Checkup on Safer Internet Day. These accounts can't sign up for Google One if they're free users and want to upgrade, and don't have Google One if they're already paid Drive subscribers. Google says, "There are some technical complexities we’re working through to make sure that you get your Google One benefits while retaining your promotional storage. We don’t currently have a timeline for when you’ll be able to upgrade to Google One."

Users who bought Drive storage between June 14th and August 14th, 2018. Apparently these accounts got the email that they were upgraded by mistake, because something is delaying the rollout to them. They should wait for another email titled "Changes to your Drive storage plan," and their upgrade will happen in the upcoming weeks.

All G Suite accounts (with or without additional paid storage)

Accounts marked as "Legacy" in drive.google.com/settings/storage (with 20GB/$5 annually)

If you thought you were eligible for Google One and haven't received the proper upgrade yet, these exceptions should clarify the situation for you. As always, with a company whose userbase is as large as Google, some features rolled by one division in the past might cause friction for other features being rolled by another division now. This seems to be the case here and patience is all we can recommend.