It’s definitely not just a couple of seconds, unless you have a very lightweight OS and only 1 or 2 apps to work with. And no matter how little extra time it takes to cold boot the system, there’s still no benefit to doing it that way, so no matter how little that time is, it’s still wasted.

As I mentioned, one is free to use their computer however they wish, but it doesn’t make it not wasteful to shut it down. If grabbing something to eat was part of my daily routine, I’d grab it beforehand, instead of needlessly going back and forth, wake the computer and use it immediately.