What possible app outside of photography are you running on an iPhone 13 that you can't run reliably on a 6S?
The SE might be my next phone... still using an iPhone 7, but I'll stick with the 7 until the hardware can no longer get the latest OS. Weight, battery life, and touch id are important... Step up weight 30%, and I'm having to possibly get a strap to keep the phone on my arm instead of pocket when running.. battery life.. .well, its tied to a bluetooth glucose sensor with an app running 24/7 in the background so that's of utmost importance. I still get that with my 7. If that means smaller screen, and lower weight for all day battery life, fine by me.
Touch ID? I subtly use it quite a bit. Start my car, plug in the phone... oh yeah, got to unlock the device and I'm driving down the road... quick touch on the button while I watch the road... done. A lot of other times, its orientating the device by feel when I have arms full of bags trying to look something up quickly, or, its pitch black in a room looking to plug in a lightning cable. I know.... Qi chargers can do the same thing, but I don't have one of those in as many spots as a lightning cable around the house.