Nothing but it's much more expensive. You need 20 accounts that have more stake than the rest of the community instead of just 1.

If I have 100 mln HP I can choose all block producers that I control - and they do what I want, for example nullify your account.

With "my system" I can choose only 1 block producer - nothing changes. I can also split my my stake between 20 accounts (5 mln HP each) but still I don't have majority to put on top block producers that I control.

Basically the current system allows small group of people to control the whole network - this is why no big investor even looks at Hive and why we will keep declining with occasional pumps.