I think they really care about two things: VAT and cryptocurrency. Passports are required to prove you should or should not pay the 19% VAT, and crypto (namely, SIA) destroy their servers.
(But I believe the KYC rules aren't only because of this.)
I've run into this with a few different German businesses, I don't know if I'm right or they are, but it seems like they don't _have_ to charge me VAT. Which is underlined by the huge "import VAT" bill I'm dumped with when I have physical goods delivered to me in the UK.