They do have to prove who you are, and to do that you need to show your ID(s) and they need to check it in their system. I don't understand your comment.

I already have to log to their website with 2 factor authentification. I had to walk and physically present my id card, install the numerical identity app. That should be enough.

Also, apart from reuploading IDs, they ask for information such as age, name, place of living, and a thousand more things that they already have and doesn't need to be provided to establish that you really are you.