It's seldom invisible, but in my experience how visible it is depends on the size/modularity/performance/etc of what's being swapped and the underlying hardware.

On my 8gb M1 Mac, I can have a ton of tabs open and it'll swap with minimal slowdown. On the other hand, running a 4k external display and a small (4gb) llm is at best horrible and will sometimes require a hard reset.

I've seen similar with different combinations of software/hardware.