Quoting the op:

> The Damage:

> I effectively have over $30,000 worth of previously-active “bricked" hardware. My iPhone, iPad, Watch, and Macs cannot sync, update, or function properly.

(I assume these can be re-sold? They do mention that they can't sign out)

> I have lost access to thousands of dollars in purchased software and media.

Should the "purchased" software and media be within the data export scope?

> I don’t have a 6TB device to sync them to, even if I could.

...yeah.

But let's say we limit ourselves to stored bits.

How should the service identify the person asking for data export? Does your regulation imply government id registration for all internet services? Is that what you actually want?

What if the service is e2ee? How do they deliver "human readable file formats"? Are we also banning e2ee?

What do compliance requirements imply for people's ability to start competing services?

You are proposing to replace a very tiny bit of personal responsibility (having backups) with a very intrusive, and highly consequential, legal mechanism.

EDIT: Though I would, of course, support a requirement for these services to properly warn users (on the registration page, not buried in TOS small print), and provide thorough instructions for making backups to external storage connected to any of the devices they support.