The sRGB profile does have a true TRC and not a gamma curve and Photoshop honors this. In Color Settings, when you futz around with the gamma settings, you'll probably not get this TRC. IOW, typing 2.2 gamma should provide this while the actual sRGB profile has that funny bump down in the shadows.
If there's some old software that accesses the sRGB profile as designed, and uses a simple 2.2 gamma curve, well you probably don't want to be using that product assuming it can even run on a modern OS.