You are thinking about Smart Select? I just take fullscreen screenshot and then crop it if I need part of it. Did it even when I had previous Smart Select version. Overall I think new version with all previous 4 select options bundled in 1 is better.

Not sure if Google Lens counts as AI, but Circle to Search is a cool feature. And on Samsung specifically there is Smart Select that I occasionally use for text extraction, but I suppose it is just OCR.

From Galaxy AI branded features I have tested only Drawing assist which is an image generator. Fooled around for 5 minutes and have not touched it again. I am using Samsung keyboard and I know it has some kind of text generator thing, but have not even bothered myself to try it.