I've already made a comic about the prerequisites needed in order to make a relatable foreigner in an anime series. This comic pokes fun at how a lot of isekai series have a protagonist that was once a salaryman in their previous life (i.e. Overlord, That Time I Got Reincarnated as a Slime, The 8th Son? Are You Kidding Me?).
Honestly, not sure whether having your main character start off their life as a salaryman means more sales overall, but I do think it is easier to sympathize with them. They might be overworked and underappreciated, but companies wouldn't survive without the determination and loyalty of these hardworking people. Here's to the salarymen and whatever they might be reincarnated into in their next life, as well.