mostly because it's built by people who have zero experience writing servers

clients should be more like peers than clients, and they are to some extent but oversimplifying the query interface has dumbed down the challenge for client devs

and it's not an easy thing, personally, the reason why i use Go is because i mainly write servers and concurrency is essential to simplifying features and scale, but you get stuck with dumb heavy or foreground/background thread architectures on most UI dev languages