Watch 10 things I regret about node. js - https://youtu.be/M3BM9TB-8yA from the creator of both node and deno to undersatnd his motivations behind the deno project. A very intriguing talk.
Expect to see this in "n things I regret about deno"
You are right, we will try to get rid of it for some faster serialization mechanisms (after some huge internal refactor lands). See the talk I posted, Ryan mentioned about it near the end.