Google's G Suite, which includes Gmail, Google Docs, Hangouts, Meet and other apps, quietly passed a major milestone at the end of last year: It now has more than 2 billion monthly active users, G Suite boss Javier Soltero told Axios Wednesday.

Why it matters: Long seen as the upstart challenger to Microsoft Office, Google's productivity suite is now one of the two incumbents, facing fresh rivals of its own.

"That's a staggering number. ... These products have incredible reach. Changing the way people work is something we are uniquely positioned to do."

— Javier Soltero

Soltero declined to offer a breakdown of how many of those 2 billion users are for products beyond Gmail or how many are paid versus free.

Driving the news: Soltero, who joined Google from Microsoft last year, said his focus has been on doubling down on features that make G Suite unique, like its robust search, conversation focus in Gmail and built-in collaboration.

Once a startup CEO himself — he sold mobile email app Accompli to Microsoft — Soltero now touts the benefits of going with an established player, rather than some company that might not even be around a year from now.

Yes, but: The presence of so many startups out there shows there is more work to be done, Soltero said. "This is not a solved problem. Nobody has run the table on communication and collaboration."

As for what distinguishes Google from Microsoft, Soltero pointed to its Silicon Valley culture: "I don't feel the need to be quite as outspoken here," Soltero said. "People do a lot more self-examination here, which is great."

What's next: Soltero said to expect the "smart compose" feature — which suggests email replies, for instance, based on the content of the message — to expand beyond Gmail and Docs. The feature, he said, should go everywhere it is prudent to do so.

He also sees room for improvement in better integrating the separate apps. "I think we still have work to do," Soltero said.