It’s true that the current income tax has shortcomings due to the mobility of capital owners. I think it would promote competition to focus more on wealth taxes on immobile assets (on e.g. land, patents, spectrum, and ownership of networks) as an alternative to some income taxation. See e.g. Glen Weyl’s book Radical Markets on this topic (https://www.amazon.com/Radical-Markets-Uprooting-Capitalism-... https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2818494)