Yes! The steam controller was legitimately incredible for first person games. The combination of left joystick and right touchpad was incredible once you got used to it.
I love my steam deck, but I was really disappointed with the touchpads... they are just too small too really use for much of anything other than menus. As a result, I really only play 2d games, since I hate 2-stick controls...
For me, the biggest strength of the steam controller was using the right trackpad for FPS-style games... basically a virtual trackball mouse. Once you got used to it it's incredibly responsive and a huge upgrade on a joystick.
I never managed to get my deck to work like that. The trackpads are just too small and don't seem as responsive somehow? Granted, I do have quite large hands