Laws and rules are far slower to adapt than the workarounds that bend them. And clear ownership says little. Everything can simply point to a more or less real identity that nobody will ever find.
Don't get me wrong, I'm not against such rules. I'm just saying that the likelihood of them achieving the results we imagine are slim.
Corporate ownership is also traded as a commodity. The US Auto Parts Northeast Region Transmissions Warranty subsidiary is required to hold assets sufficient to bond the warranties it issues, so instead of keeping a large pile of hundred dollar bills on the coffee table, it holds shares of the parent company and you now have circular ownership. If the parent company is loaded up with debt then you might find that the subsidiaries like that own the majority or entirety of the parent company -- without even necessarily realizing it.
You also have the problem that people willing to commit fraud are willing to commit fraud. Convince some credulous victim that all they have to do is put in $1000 and sign some papers and they can invest in The Next Big Thing and they've not only scammed them out of $1000, now it's the victim's name on the shell corp.
Generally speaking identifying people who don't want to be identified is hard, the methods effective to do so oppress innocent people more than anything, and it is best to look to other solutions. For example, if you discover people are publishing misinformation, show the truth to the same people who saw the misinformation.
Finding an appropriate n might be a delicate, many big (legitimate) businesses have really complicated ownership structures. Then you have to task someone with validating all of this. Whose expense is it to do the due diligence and check everything? WHo takes responsibility for failures in this regard? And finally it will mean some business is lost on both sides and it might be a lot of money.
Banks have anti money laundering policies yet still find ways to go around them all the time because they want the business. Banking secrecy wasn't there to protect privacy but to obscure shady activities. As I said, it's good to have the rule and I'm not against it but I have the feeling people have some unrealistic expectations from this. They just raise the bar a bit and filter out the "chaff" while still allowing larger interests to prevail.
It is something between 10 and 13, if you accept that governance structure of an organisation must match its social communication structure. It is something between 14 and 16, if you accept that governance structure of an organisation must match its business divisions. Any n>16 is prone to communication shortcutting.