It's the same reason I was nervous moving our company domain to a .ai TLD; your entire presence, identity and trust is now beholden to the whims and political winds of a Caribbean island smaller than Topeka.
It's a real risk. The British Indian Ocean Territory is going away, and by ICANN's rules, that means .io should as well.
It's not anymore: "in April 2026 the implementation of the agreement was put on an indefinite hold due to opposition from US President Donald Trump." So whatever ICANN was going to do with .io, it's all on hold for now.