Swede here. I would not want to go back to days without BankID and related tools. That being said, the implementation has some less than desirable features. It's privately owned by some kind of joint venture by the banks. It only supports the major OS:s. So you're pretty much forced to own a Android or IPhone to function. Also, I haven't had the need to do this myself but taking care of somebody else's legal dealings (like an old parent or children) I understand is quite cumbersome. I think that kids are kind of forced to get BankID when they are quite young.

There are alternative implementations but I'm not aware of anyone that uses them.

It's more like we've slipped into this solution out of pure convenience than having made a deliberate choice.