Almost nobody reuses it. Identity & signing is the program that does: establish once at the highest standard the law recognises, then sign, authenticate and authorise with the same proof.
It is also the program that decides what a signature is worth. Simple, advanced and qualified are not grades of the same thing; qualified means a court starts from the assumption that the signature is valid, and that difference is the reason the program exists.
Legally binding across the EU.
Envelopes, composer, dashboard, and hash signing where the document cannot leave your side.
Prove once, use repeatedly.
European national schemes and the EU wallet behind one interface.
Remove sensitive content from a signed document without invalidating the signature.