Depends what market you are in. In the UK I would estimate M365 usage is ~100% of local/national govt.

And in terms of classic 'corporate' sectors like law, finance, etc, it also close to 100%.

Whereas in "tech" it is far more likely to be Gmail.

I _still_ get people who are non technical that work in 'corporate' sectors that can't join a Google Meet because they think it is Teams. They literally haven't ever used a Google meeting before.