There are some easy optimizations wins for this page but none of the top ones are framework related. Maybe with the faster build times they can easily optimize images and 3rd party dependencies. As someone else pointed out, nearly half that data is unoptimized images.
For the curious, google's current homepage is a 200kb payload all in, or about 50 times smaller.
Who remembers sprite sheets? Does that give my age away?
I did an optimization pass for a client once where I got rid of a ton of the sprites but didn't have the energy to redo it all, so it just had huge sections that were blank.
Super snappy loading afterwards though.
Yes, good times! With http2/3 they don't really matter anymore though, you get similar benefits from request pipelining.
Spriting is actually harmful for performance except in specific HTTP-1 scenarios.