[Mawr]

That past criticism was and is correct, proven by the fact new Java GCs like ZGC were deliberately designed to offer few knobs.

Go isn't getting any new knobs, there are only two; that's nothing compared to 100's of options that old Java GCs had. Completely incomparable.

> and turns out various GC algorithms are actually useful.

I don't know what you're trying to say here, but I think I know why — you don't know either. Stop spitballing.

There are no "various GC algorithms" at play here at all. There is just a new algorithm that performs better. You can read all about it here: https://go.dev/blog/greenteagc. It's not an optional alternative GC, but a successor.