Where does Apple fit into this mess. My PC is aging, but it’s not quite done yet. When I replace it, I may go Mac.
Does Linux support Photoshop/Lightroom?
Nope. Linux has GIMP as the closest thing to Photoshop and I imagine there's something similar to Lightroom.
There's also ImageMagik which is wild because it's a command line tool for manipulating images. Yes, you do things with images without viewing them. It's actually very powerful and installed on most every web server. That's how social media sites and even most blogs can take that HUGE digital camera image and shrink the size in pixels and also the size in bytes/megabytes(optimize) etc so that the web page they end up on won't take minutes to load and the server hard drive won't fill up. There's a reaon image upload is not a thing here on FR. Oodles of disk space required. Many forums do allow image uploads and I'm sure all of them utilize ImageMagic to turn that 4gb cat pic from soneone's phone or digital camera into a 200 kb cat pic.
It's like Photoshop's Batch Process but photoshop will open each one graphically, even if only for a few seconds, and may freeze your system. ImageMagik just plows through them in the text version of them.
My sister is into genealogy and we have hundreds of old pics that had been scanned. She wanted them on a genealogy website so I ran them all through ImageMagik with a maximum dimension limit of 1024x1024px while keeping the existing aspect ratio and also optimized them for small file size while keeping them sharp. Got the commands from the web and pasted them into the terminal. Did a couple hundred pics in a minute and put the new optimized copy in a different folder I created and chose. I have that command saved for if I ever need to optimize a large batch of jpg images again.
Shotwell is a photo organizer and DarkTable sounds like the equivalent to lightroom. Both get good reviews.
There is no shortage of info on GIMP out there on the web, reddit, youtube etc. There's a Windows version so the userbase is quite large. There may be more Windows users than Linux at this point due to the price of Adobe products.
Other Linux graphics programs are InkScape for vector based images - svg is native and png is commonly exported from it. Krita for digital drawing, 2D animation, popular to use with graphic drawing tablets.