[cthalupa]

As a daily Mac user for about 13 years now I have no idea what phenomenon you're talking about.

For any program that is open, even if it hasn't been in use for a while, I click it once, and it comes to the forefront immediately.

For programs that are not open, I click it once, and then if I wait for it to launch, it appears in the forefront. If I immediately click back over to my web browser and begin using it before the program launches, it does not appear in the forefront... because I interacted with another program after starting the launch.

[Clamchop]

They might be referring to how clicks don't register with an app until it has focus (the first click being to focus it).

On Windows you can, say, click once to pause on a video playing in a browser window that doesn't have focus but is visible. On macOS, it's two clicks, because you have to focus the app first.

I don't care for the behavior but it's so minor to me that it carries essentially no weight.

[cthalupa]

Ah! This does make sense. I mostly run things fullscreen on my laptop and use Mission Control to swap windows so I really only encounter this when my laptop is docked to a larger display.

It doesn't particularly bother me one way or the other to the point I didn't even think of this, despite also being a daily Windows users on my desktop computer.