That is very much _not_ the case according to the testing I have done recently.

Swift uses a lot less memory than Go unless the program uses only trivial amounts of memory in the first place. Using interfaces in Go data structures makes the difference even more pronounced.

On top of that, all runtimes that use a tracing GC require tons of spare memory at all times unless programs are very carefully written to avoid memory allocation.

That said, Swift has a few very weak spots when it comes to memory. Most notably the String type, which is terrible on all counts, but that is a whole different story.