Non-kosher kitchen question

I’ve been watching a lot of videos and learning a lot about Jewish customs and I see that in a lot of places they travel they don’t use non-kosher cooking surfaces and food preparation areas. I also learned the rule of batel beshishim, wouldn’t this eliminate the need for separating your cooking areas since any trace of non-kosher food would be minuscule after a simple cleaning? Or is there another rule that I’m missing saying that outright requires you to prepare in a different cooking area?