I don't think pcsx2 team used fraps in the first video you mention.
I actually think they used the internal recorder
indeed they do, fraps simply captures whats on the screen whereas the internal recorder fetches it straight from the GS
which means that though the game may be lagging, it simply captures it frame by frame and assembles it into a working product
Hello again, I am back here again for this old post to just say that I was just dumb XD Fraps records by pressing F9, so when I did press that button, it changed to software too, thus the lag!
Lol facepalm!
I have seen this happen a couple of times before. I assign the ` (e.g. the key to the left of the numeral 1) for my record button in FRAPS and Bandicam because of this.