Not relying on Deno's permission system will, in practice, mean just allowing everything or using Node instead of Deno. I can't for the love of god understand why that's better than using a permission system that provides some more protection than just about any other currently-commonly-used backend dev platform. Nobody at Deno is suggesting that their permission system solves all your security risk.
I bet "just allow everything" is not what the top poster intended but that's the takeaway. How many Node deployments do you know that use OS-level protections to eg disallow Node from spawning child processes?