If you're skilled, take enough photos, and are skilled at developing film -- you could take award winning photos with a Brownie camera or even a an old Kodak Ektra. ;-)

I'm not sure that most people are aware but Ansel Adams -- an absolute master -- used the most advanced equipment available to him at the time. He was gifted in so many ways and could have won awards with a Brownie, but he used the most advanced equipment he could. If you've ever seen any documentaries of him preparing for a photo shoot -- you'll know what I mean -- station wagon loaded to the gills with camera equipment.

If Ansel Adams was around at this time -- he would probably be using a $20,000+ dollar digital medium format camera (the camera he used most was an 8x10 medium format film camera). Pretty sure he would not be using an iPhone. :-)

This is true! you could literally be updated, or upgraded right out of your current hardware, which many of you know, a computer with good photo processing capabilities can be quit expensive. If you don't make money from photography and post processing then paying for a subscription is unjustifiable for the hobbiest especially if on a fixed income.
Affinity Photo, IMHO is probably the best choice for an Apple user who may not be upgrading their equipment for a long time if not ever. When I bought Affinity they promised updates and upgrades forever. Even if they cannot uphold that promise this program is a very powerful photo editor that could continue to be used for years.

Okay - I can see from many of your responses that I failed to phrase my query properly.

So... can I try again?

1) I'm newly widowed, moved to an entirely new part of the country, am still moving in, have no family support here, am financially limited, and am fighting colon cancer at the same time;

2) While photography is not the top priority in my life at the moment, it is very important to maintaining a certain quality of life;

3) I have made a substantial investment in time and money to acquire and learn to operate fairly sophisticated equipment (most notably my Nikon D750, and my best lens, the 105mm prime, as well as the MavBook Pro from 2014, which has a particularly sophisticated color processor or whatever you call it, and I print my better work on an Epson R2880.);

4). Aside from the obvious competing priorities in my life, I now have to deal with the obsolete photo editor that I spent much time mastering in the past - that is, Aperture 3 - thank you, Apple geniuses, for abandoning the application that you pushed so successfully for all of us to rely upon;

5). I tend to swing between the 2 extremes of using my iPhone 6 Plus to take photos of nearly everything that catches my attention, and surrendering to the perfectionism that requires me to set up my tripod with my D750, my 105 lens, my backdrop of black velvet, sometimes accessory lighting, and taking zillions of photos while changing various settings on Manual (which I always shoot in - that's just how my late husband taught me), including always shooting both in jpeg and in RAW - or nef, or tiff or whatever;

6) until now, I have not attempted to edit in RAW, because I couldn't or wouldn't take on the massive new learning curve that would require;

7) I also have never edited in anything but pixels, for the same reason as above; BUT,

8) Since the Aperture phaseout is forcing me to find new editing software, I'd like to find one that isn't significantly different from Aperture, but will allow me to build on what I do know, as well as to provide the opportunity to learn editing RAW images, and working with a non-pixel editor; and so,

9). While I'm acutely aware that I'm asking for the impossible, I'm trying to find a compromise that will work for me at the skill and interest level that I have now, leaves room for a steeper learning curve, and comes at a price somewhere below exorbitant. Can I stipulate an outside cost of $75 or so without incurring vehement protests that it doesn't exist?