Note that that article also praises async Rust.
Go's GC is hardly state of the art.
I got no horse in this race -- I like both Golang and Rust and use them for different things -- but as far as I can tell, Golang's GC has improved a lot.
Not sure where does it stand on a global competition rating board (if there's even such a thing) but it's pretty good. I've never seen it crap the bed, though I also never worked at the scale of Twitch and Discord.
Until all the work you're trying to push is generating so many allocations that your GC goes to shit once every two minutes trying to clean up the mess you made. (https://discord.com/blog/why-discord-is-switching-from-go-to...)