Speaking for myself I wouldn't want to give my driving licence birth certificate info to a mere online shop, as it contains info an identity thief would love to have, and over the period of years or even forever it takes only one mistake with my info or careless handling or one rogue employee or a good hacker.
In particular, just for an online shop, I wouldn't want to send copies of those valuable documents in the form of scans. "I enclose a copy of my birth certificate and driving licence," says an ID-thief pretending to be you. Those two are two of the most useful documents for an ID-thief.
When I (three times) had power of attorney, despite instructions to send certified copies of certain documents, I sent out redacted photocopies of a certified copy of my relatives' documents like birth certificate, bank statements and Lasting Power off Attorney (which contains, for instance, mother's maiden name, full names/addresses/D.O.B./job info/contact info of attorneys and other relevant parties - real gifts to an ID-thief). I told the recipients to obtain a "proper" certified copy at their own expense (none did) and no one raised queries or mentioned the redactions. Just because important organisations e.g. statutory undertakers or government agencies demand certain things doesn't mean you have to comply, as privacy and security for you or someone you act for are more important (you can always send an unredacted copy later if they insist). eBay gets away with being so demanding because, bottom line, do you want to buy/sell on eBay or not? so it means deciding one's priorities. Are you really so constrained that you must give unredacted personal info just to buy or sell a particular item on this particular platform or go and obtain it in a physical shop or have someone pick it up for you?
