1. Right now, corporations can change jurisdictions for more favorable taxation - or can save taxes by positioning key parts of their businesses in differing jurisdictions. All legal. Smart.
2. If every country has the same taxation, corporations are stuck.
3. Once stuck, they can be plucked mercilessly.
4. Since they will pass this on to consumers/end users, the government can raise taxes without provoking citizens.
If corporations are stuck, they can be manipulated with social credit scores (ESG).
It is another way of tyrannical, global control of everyone by a tiny, connected oligopoly.