I cannot trivially get the whole database, no. But I kind of fail to see what a malicious actor would do with a large database of public information that they couldn’t otherwise do. The system is designed such that you can’t really do a lot of malicious stuff with just public data, and the stuff you can do (scam calls, etc) is probably not meaningfully more effective if you have the whole database than if you do manual lookups or web scraping. I’m open to being proved wrong about that however.

Basically: obviously it's not desirable to have that full database in the hands of a malicious actor but I'm not sure it's such a big deal either. Again, it's public data by design.

Yes, you can buy the database for the entire population. There are commercial vendors for this, one of them is Dun & Bradstreet (Bisnode Dun & Bradstreet Sverige).