Looks to be a bit more bent than what could be salvaged by simply bending it back but at this point you have nothing to loose, just don't ride it until you add
a bit of a "sleeve" on the outside or inside to reinforce the damaged area.
I had a frame that had a really similar kink in the seat stay same place. Since he metal hadn't cracked or split it was just bent,
an old-timer simply bent it back in place and I rode it for another
25,000 miles. It was a nice Italian built frame 1979 or so. One of the best rides of any bike I have ever had. T
I am from the school of "every frame is worth saving if its save-able"
I see steel frames entering the hallowed world similar to that of vintage vinyl
records.. If you love the frame save it.