> One would think that if there is truly a Europe wide market for such an unlocked device a competitor should be able to challenge Apple and Google dominance.

The problem is that such a device doesn't really have a chance because it's not compatible with existing infrastructure such as WhatsApp, Instagram, your banking app, what-have-you. It could be the best device in the world, but there's always a catch-22 problem with software that's fundamentally closed and can't be implemented by a third party.