In this episode, Surma talks about a presenation-maybe-soon-to-be-a-proposal "JS0", which explores the idea of splitting JavaScript into two specifications: JS0, focusing on security, performance and capabilties, implemented by engines; and JSSugar, focussing on developer productivity and syntactic sugar features implemented by build tools.

Notes & Corrections:

Yes, I know, people still do have to step through assembler. But I stand behind the essence of my point: The debug symbols for compiled languages feel very reliable. We should be able to at least match that reliability in JavaScript.
Guy Bedford currently works at Fastly.

Resources:

Previous episode on Shared Structs
The infamous slide deck
OTMT episode on SourceMaps on source maps

TC39 Roundup Drama Edition Part II: JS0 and JSSugar