This one is definitely the hardest and is the least mature. Have you managed to get off Google on your phone?
I'm using GrapheneOS (Degoogle'd android) on a Pixel 6a. The irony isn't lost on me that I had to buy google to get off google.
I had tried Pinephone and Plasma mobile, but it still needs more work and I needed a phone sooner as my old one was failing.
How about you? Did you manage to get away from Google?
In the UK, banking apps are optional, I can use website in browser.
With GrapheneOS, you can install Play apps sandboxed and with dummied google apps and control how much of the file system they can see etc.
I would assume outlook has a web client. Not sure what InTune is so cannot comment.