It's not what people mean when they say GC though, especially in reference to games, where you care about your peak frame time more than about your average frame time.

Reference counting can also have very bursty performance. Consider what happens when you decrement the last reference to an object which is the sole remaining reference to an entire large tree of other objects. This will trigger a whole cascade of subsequent decrements and deallocations, which can be arbitrarily large.

Of course, you might say, "Well, sure, but your reference counting implementation doesn't need to eagerly deallocate on dereference." That's true! You can write a ref counter that defers some of those deallocations or amortizes them across multiple operations.

And when you do that, now you really do have a garbage collector.

See: https://web.eecs.umich.edu/~weimerw/2008-415/reading/bacon-g...

People should learn their subjects properly, not street knowledge.

You should watch some of the more recent Gamers Nexus videos... the average frame pacing counts for a lot, and they're making a concerted effort to show this, as it does represent the level of "jank" in games very well.