Interesting question. Interesting to me because it seems the premise is your closing comment, "I am wondering if i need to step my game up or if it's just for show in videos."
Your game is YOUR game; don't do something just because someone else does.
I, like you, am a professional. I have been in it over two decades now, and I definitely process product & have seen scores, if not over 100 other Cooks & Chefs, process food at the rate you are commenting on, but only when it helps us. It's not rare... at all.. it's the norm. Sometimes it's because we need to fill a deep lexan with product; other times it's because the bachelorette party is huddled giggling on the counter of the open kitchen. You gotta do what you gotta do to get the job done... completing the prep list or making your intro - whatever it takes.
You reference chopping a lot of mirepoix for your stocks, but your chicken is probably no less than 60 minutes, your re-boils are probably quite longer, and your veal stock is a shift or overnight. All of these stocks have no need for a dice because they have so long to cook; maybe the chicken if you're banging out a quick light version, but even still, they would be large dice. A dice, as you see in all those videos, would be used for a quick fire stock such as a fumet or a court bouillon where you are trying to extract the flavor in short order therefore necessitating a small quick cooking dice.
Is the focus solely on speed when a video like "speed onion" is produced? Obviously, yes. Is it ego? Of course, what other purpose does it serve than to brag, but bear in mind, some of those videos you see here on this site are produced in working kitchens. Yes, if there's time to set up a video, you're obviously not weeded, but the food is still being processed at work for work.
Just keep chopping away, and the speed will come. Remember this though, consistency in your cut is nearly always paramount. If it's so a micro-brunoise garnish looks awesome or so a vegetable cooks consistently amid it's dish... consistency is paramount.. speed comes with time & the balls to get cut.