Much slower, why?
If tomorrow means we're going to give up serving any HTML on first render and pretend that performance doesn't matter, then yes, it's built for tomorrow.
As an aside: Meteor is in the same slowly sinking boat. React is not as you can easily render server side before pushing that initial page to the client.
I expect a lot of other frameworks take a similar approach not long from now.
Secondly (and I already linked this in a separate comment), I built a very ugly but effective reddit angular client that receives no HTML whatsoever and renders pretty much instantly. This is in Angular 1.3 and much slower than Angular 2.0:
I am not that into webdev, but shouldn't a page like HN be fast TODAY, as it has very basic functionality (CRUD)? I mean if this is slow, how can I expect acceptable performance from involved applications?
The fact the site then loads content from firebase is obviously a problem, but it's not so much firebase's problem as it is of the codebase itself - in an ideal world it should be rendering the initial HTML to send to the client on the server.
I have seen React based websites with server side rendering work with firebase with much better performance.