Yes. I use ready-made designs for my work. I believe this is a way to optimize workflows. It seems to me that there is nothing wrong with the fact that I don't spend several hours to draw realistically each model of the iPhone, but use these mockups
https://www.ls.graphics/free-mockups/free-iphone-mockup . By the way, unlike many online graphic design resources, on this site you have free access to all mockups. This is really a rarity for online portals.