I have a Note 20 Ultra and S20 Ultra, on both if you want to speed up the shutter you need to use the "Pro mode". You can adjust your shutter, focus & aperture in that mode. It's still basic compared to a cheap DSLR, but you can't take one of those with you everywhere compared to a good camera phone!
Owned everything from the original Note to S22 Ultra. Disappointing that Samsung does innovate as they used to.