@bennett-family Before we get into pros and cons, I would ask two questions:
Can you afford Lightroom? You were originally looking for free software, so is a one time $150 purchase even really on the table at the moment? If not, you don’t have to worry about that option. If it is in your budget, … why are we talking about GIMP again? 😉
What are you planning on doing with the software? Software is built for different things and while you can often make it do things it wasn’t built for, it just makes sense to use software for the purpose that it was built for!
These things thoughts (budget and what you actually are going to be doing) should be your guiding factors in choosing your software.
Quick disclaimer, I have never used Lightroom or GIMP personally (Affinity all the way!), so what I’m going off of is what others have told me, what I have seen in tutorials, and what I have read (online reviews and such).
Pros: Advanced color editing; advanced RAW editing; industry standard; built in file and organization system; wealth of resources, tutorials, and books, so it will be much easier to find wholesome, “Lenspiration approved” content; non-destructive layer based editing; works with Adobe Photoshop well.
Cons: Fairly expensive monthly charge or a one-time payment with no updates; limited text and photo manipulation capabilities
Pros: Inexpensive to purchase a lifetime license with updates; Advanced photo and text manipulation; superior selections and masks; works well even on less expensive computers; solid color and RAW editing; Blend modes; non-destructive layer based editing; workflow and keyboard shortcuts similar to Adobe photoshop;
Cons: will be harder to find tutorials, resources, and books; might be slower for large batch edits (does have batch capabilities, but I’ve never tested them out or compared it to Lightroom.); limited support for photoshop plugins.
Pros: Free; photo manipulation capabilities, sometimes; many plugins to extend functionality;
Cons: no built in capability to edit (or open) RAW photos (photos must be converted with a plugin to open in GIMP); hard to find resources and books, but you should find tutorials; steep learning curve for beginners; DESTRUCTIVE EDITING (no support for adjustment layers. It doesn’t seem like a big deal until it is, trust me.).
Again, keep in mind the only software in this list I personally use at the moment is Affinity Photo, but I’ve seen enough of Lightroom and the Adobe apps to fully respect what they are and what they do and enough of GIMP to… as much as I appreciate free and open source software… not like it, frankly. I moved from a destructive photo editor a while ago (Pixelmator, available on iOS and Mac) to the non-destructive layer based editing of Affinity Photo and the difference is night and day.
As far as my recommendation goes, unless you are planning on getting Adobe’s $9.99 a month photography bundle, I wouldn’t recommend getting Lightroom unless you plan on sticking with Adobe software. For my money, I would HIGHLY recommend Affinity Photo. Yes, I’m biased, but for the beginner photographer strapped for cash without the need for advanced batch processing* or file management, it is better to have great color manipulation and fantastic photo manipulation available than fantastic color manipulation and limited photo manipulation. And, at $50, you really can’t go wrong!
It will always be subjective, but things break down to this for me.
Avoid GIMP unless you don’t want to spend any money at all.
Go with Affinity if you hate subscription charges, don’t like Adobe for some reason (hint, subscription charges), don’t have a ton of money, or want to do more than just color correction in one program
Go with Adobe if you can afford it, want to be able to follow lots of YouTube tutorials, find Lenspiration Approved books and courses, or plan on using other Adobe apps such as Photoshop.
*Affinity does have batch processing, as well as superior support for 360 degree photos and panoramas, but I have yet to test it out, so I can’t speak on it yet.