> implementation bugs. Source: have worked on a client-side implementation well because the hard part is the client-side. caching is a client-side only thing w

> implementation bugs. Source: have worked on a client-side implementation well because the hard part is the client-side. caching is a client-side only thing with http, keep-alive is a thing that a server pushes to a client, the same with chunked transfer, which is not as easy to implement for a client like it was with content length. basically a server does only need to implement certain headers, but a client needs to know all. also most clients even accept bad servers, like content for head requests, etc.. most stateless protocols put a lot of burden into clients. h2 on the other hand is stateful and keeps the same hard semantics onto the client side and also makes servers more complex, because it's a state machine.