Nowhere does that require you to go and get a DUNS number, which is onerous for a single developer to do without the infrastructure of a company.
Which is exactly the same policy as Apple.
It seems kind of odd to me to rely on some kind of external hidden "credit agency"-style company for this? And why would DUNS want to know about some kid in their basement in Bangledesh making (non-malicious) apps, and why would the kid want Dun & Bradstreet to know about them? It makes no sense at all.
Youc an see the zeitgeist forming around corporations wanting to lock out any small unlicensed company from working on phones.
The key is mostly fascism in the guise of "security". Witness stuff like the ICE tracker app. Google would love a way to freeze out both it's appearance on the app store and any developer who'd program similar.
Over the years, it seems Google has been trying to have their cake and eat it too, by basically subsuming others to use Android through this appeal of a more free and open operating system ecosystem, but have tried to slowly close and close it down now that it has won the other half of the market on that promise.
This feels more sly, because it's kind of a bait and switch. Apple never made such claim and was always upfront, so while I don't like it, I never bought into it in the first place for them to have the rug pulled under me after giving them my money as Google might be doing.
It's not that the identity prevents malware/abuse, but publishing any malware to the store burns the identity and establishing another is harder than simply coming up with a new email address. It's not necessarily the best scheme out of there, but it makes sense given their apparent goal.
Google Play is not open source. You're still free to sideload on phone that use vanilla open-source android like the Fairphone.
They can already target malicious apps via Play Protect, including presumably all apps signed by the same signing key, so from that point of view no change would be needed. What this is presumably supposed to achieve is rather making it harder to rotate your signing key after it has been burnt…