However, this coalescing was very complicated, both in the specification and implementations, due to the dynamism of computed property names for accessors. Coalescing was a big source of overhead (e.g., in terms of code size) in polyfill implementations of "Stage 2" decorators.

Code after:

We don't use "attribute directives" much which makes things easier.

I was confused as to why there is a dual system running on, there might be reasons for that but let's fix this situation by only using Webpacker to generate our assets.

I applaud the effort to simplify things for 2.0! The current syntax feels sprawling and ad hoc.