Microsoft absolutely dominates corporate IT. Their Office 360 delivers to much values at a low cost that the corps suffer from mediocre MS products because it's all there through a single subscription.

Same for the Google options; except the Google options tend to make non-backward compatible changes and often only go 90% of the way to meet the competition in terms of features. Even their spam detection is not where postini had it years ago.

I worked in Google Workspace.

A CIO needs to see significant upside in choosing a non Microsoft solution to take the risk of not going with on-prem /cloud AD.

Very few enterprises, this is an understatement, use Workspace exclusively.

They need Active Directory Domain Services (on-prem AD) regardless and it is their source of truth (typically syncing to Workdpace for users/roles). The tooling and expertise is in AD. Azure AD will always have a better on-prem to cloud story than Workspace (or any competitor). Plus their licensing makes it a no brainer. It’s a very strong moat.

With AD we have SSO integration with a whole universe of mediocre apps, Jira for instance

I need to always give a password in Jira.

Jira, and the whole of Atlassian Cloud services, bundle SSO as a separate service you pay for. It's called Atlassian Access and it costs $4-$2 depending on number of users, so many companies skip it because it easily doubles your Jira/Confluece costs.

sso.tax

Jira’s cheapest license is $7.5, Atlassian Access as its most expensive is $4 a month. It will never double your Jira bill.

Security tax