Layers is the only thing I use PS for. It's still an important tool BUT you certainly don't need the latest version of PS for stuff like that. I had a shoot recently where the multiple buffered shot (I always shoot multiples of any big group shot) had various people blinking in each frame so I used PS to copy paste eyes and blend into one master layer. Stuff like that you can't do. I am on PS5 though, it does the job and is an essential part of my Lightroom workflow, maybe not for every shoot, but when the need calls for it, there isn't a better alternative if you're accustomed to Photoshop.