I can guarantee some dutch banks are also locked into MS. Maybe not the big ones that actually need to care about tech, but the ones that don't care about tech went head-first into Microsoft Suite these last few years.
Its' an awful sight. What's worse is that there's no argument for this extra cost (apart from maybe vendor lock-in), and now no one knows who to blame for the big bill that comes in every month.
The big green one absolutely is ms heavy place.
We switched completely to Microsoft/Azure a couple of years ago. My previous employer as well.
There was no stopping it, I'd tried and they looked at me like I'm crazy. "Everybody else is doing it" is a very strong argument.
At the same time, a very popular open source security package that I wanted to use was deemed a security risk because the maintainer has placed Ukrainian and Palestinian flags in the readme.