Yea, it's only Edge, but if you look at WebSockets you'll see that everything except Opera Mini supports them - so you can get (some of) the same functionality without polyfills at all.
But why willingly introduce extra complexity to the system?
Websockets are way less trivial than SSE. Polyfills for a less popular browser seem to be a simpler solution to the problem, compared to websockets stack everywhere. Even if I don't have to implement websockets on my own and would use some mature library (because bugs happen even in such libraries).
Comments
Yea, it's only Edge, but if you look at WebSockets you'll see that everything except Opera Mini supports them - so you can get (some of) the same functionality without polyfills at all.
But why willingly introduce extra complexity to the system?
Websockets are way less trivial than SSE. Polyfills for a less popular browser seem to be a simpler solution to the problem, compared to websockets stack everywhere. Even if I don't have to implement websockets on my own and would use some mature library (because bugs happen even in such libraries).