The servers I use have limits far below 1M active connections, realistically speaking about 60k simultaneously active connections. So I can't really answer that question. However, it's easy to find answers to that question online [1]. Go is not forcing you to spawn Goroutines when you don't really need them. As I said, the correct way in Go is to use worker pools, the size of which depends on measurable performance because it is connected to how much i/o each Goroutine performs and how long it waits on average.

[1] https://www.freecodecamp.org/news/million-websockets-and-go-...