The UI is more or less the same (in principle at least), but there have been major improvements in UX and under the hood. AAS, WPA3, VPN, VoLTE, 5G, SailJail, BT plus all the minor stuff like updated libs.
This would be great, but it’s also basically impossible. The both operating systems are somewhat walled gardens. This means, that moving things between different platforms is made intentionally painful. For example, the only things on iPhones that don’t use proprietary formats are contacts and calendars. Even some of the pictures and videos are using apple-specific formats, let alone notes, calendar reminders, messages, etc.
To make things easier for yourself, just use FOSS formats wherever you can. This way, you have no problem syncing files between your phones, PCs and web services.
That’s something that can be said about ~every OS, if you come from a different platform. As long as you can find what you need by using correct keywords, this is a non-issue, if I understood your problem correctly. Of course bigger platforms have a wider selection of apps, but every year we get new great native apps.
I can very well understand what you mean by this, but in some regards there has been improvement. For example, enabling microG takes only one tap. Previously, it took multiple steps to achieve that.
This one I don’t understand, but I think Säästöpankki is the only one that doesn’t work currently. Not sure about Danske though, since I don’t know anyone who uses it.
Achieving this would take multiple million euros and that’s not even counting the development work needed on the OS itself. Therefore, I think this is just simply unrealistic at the moment.
Lack of accessibility features is a big downside in every non-major OS. It boils down to the fact that development needs to have priorities and currently there are things like Camera2 API and browser and known bugs that are on top of that list.