> Can you elaborate on why you think that Firefox is inherently insecure in some way for accessing Google workspaces?

Allowing users running who knows what version of Firefox (or any "non-validated"/unmanaged browser, not necessarily just Firefox) browser running who knows what extensions can be pretty unsafe. There are lots of malicious extensions out there that are stupid simple to install.

In the Workspace world, Chrome can be configured and enforced to have certain kinds of settings applied. Only allowing certain extensions. Ensure certain version ranges. That sort of thing.