@Pompel if you have a few minutes to spend, here you have a well-made video explaining a lot of things about sRGB (and color management in general…). Spoiler alert: having a 100% sRGB workflow doesn’t ensure you that you’ll get accurate color from end to end sRGB urban legend/myths Part 2 - YouTube
@Guenterm have a look at the video, and you’ll see why most labs require you to provide them with sRGB files 
Steven.