Go was successful because it came after decades of pretty much no language putting good networking tools in their stdlib.
In before if you needed to make a highly concurrent network app you had to get into asynchronous programming that generally makes code looks shit (or at least slightly worse) and harder to debug.
With Go and goroutines taking IIRC around 8k for start you can "just" spawn as many of them as there are connections and write your code as if it was serial one. Add some half-decent concurrency primitives and it's pretty easy to not fuck up highly concurrent and highly parallel code.
https://elixir-lang.org/blog/2023/06/22/type-system-updates-...
It's not Erlang specifically, but it is a BEAM language, so tomato tomahto.
Go is used because Google and that's it.
You can tell this is an accusation thrown around by non-Go programmers because frankly, throwing around a lot of interface{} was always really inconvenient. It's not something the language trains you to do... it's something you get punished for, really quite hard.
Somehow Erlang gets this special dispensation where people get to talk about it as if it's still 2005 and it's still this unique and interesting snowflake with virtually no competition. Which it was... back then. But having successfully convinced the world that there's an interesting space there, in 2023 there's a ton of options and the point in that space Erlang staked out isn't actually that interesting or unique when you measure it by 2023 instead of 2005.