If you buy a physical book from anywhere, you own it.
Even that isn't strictly true, as IP laws metasticize and mutate over time. But its far more expensive to try and reclaim a book than to revoke a digital license on a 3rd party repository.
If you kept your digital copy of a digital book on an e-reader in airplane mode, you'd have as much access to that as any trade paperback. And backing up my collection of PDFs to a drive is significantly easier than shouldering a shelf's worth of books.
The fundamental issue with digital media is that its ultimately convenient to access a central digital archive than to keep your own personal collections on hand and catalogued. But then you have to ask the question "Who controls that central digital archive?" And if its a bad actor, there's your problem. Its the same problem physical libraries have, too. Don't let the guy who burned down the Library of Alexandria run your neighborhood branch. Don't let Ron DeSantis near it, either.