you're talking about a google team that tested chrome on over 5,000 of its employees and not one of them bothered to open hotmail (the most popular email at the time). This was when chrome first premiered, and many popular websites didnt work in chrome.

I'm sure they use it plenty, just all in the same exact way. i have this problem because i have my personal and 2 work accounts that are customer specific.

When I worked at Google (2010), this was a major pain point. Your @google.com account is essentially a Google apps account and most people have a personal @gmail.com account. At the time, the best solution was to use multiple browsers or incognito mode.

The flows can definitely be improved and I'd attribute this to it being a hard implementation problem rather than a lack of awareness around what a good flow looks like. Most companies don't even try to support letting you log into multiple accounts at one time. Having multiple domains (google.com, youtube.com, Google Apps domains) makes it even more complex.