Linux was a corporate-level operating system as far back as the mid-90s. It was the late 90s when it started getting enterprise software for example https://en.wikipedia.org/wiki/Oracle_Database released Oracle 8 was released for Linux in 1997.
Redhat Inc became part of the Nasdaq-100 in 2005.
I make this comparison as the question is whether OpenStack still has the potential to become a full go-to alternative in the way that clients consider closed cloud systems from AWS/GCP/Azure as substantial equivalents.
Becoming a Nasdaq-100 company is a trailing indicator of going mainstream. By 2005 RedHat and Enterprise Linux had won, and Sun had about 5 years before Oracle purchased them.
OpenStack is great if you want to manage your own data center and some companies should do that. It is a cost/benefit analysis that some will make on the side of doing their own thing.