Sure they do, but all of the alternatives are not nearly as convenient. But you can absolutely get by without an iPhone or Android phone with Play services.

Effectively, for most people, they don't.

Most people make a new phone purchase impulsively when involved with negotiating a phone plan at a store or in a rush after they break their old phone and need a new one for life and work almost immediately, the cost benefit analysis for most people simply doesn't make sense unless they are naturally interested in tech as a hobby or it is related to their career (or are surrounded by friendly people who are).

afaik our digital identification system does not work well outside of iOS or Android (most of the time, not at all - since it breaks on updates and they update basically daily). so we're stuck with their duopoly. because digital id is mandatory.

Once upon a time they did support linux on desktop but then ubuntu went and decided to make a phone and linux support was mysteriously discontinued a week after.

Ok show me a phone that is readily available that has the ability to log into banking apps etc.