Adyen are the new payment processor and are a regulated entity who require a certain level of identity confirmation.

It's no different to most sellers when they had to give their ID to Paypal in the past.

I sell on Etsy and they require pretty much the same stuff BEFORE you can even open an account.

Amazon also has vetting procedures, so I'm not sure why you think Ebay is doing something that is different to how other big operators work.