I always have my camera set to RAW and JPG and looking at the Affinity interface it looks a lot more user-friendly than Gimp and Rawtherapee and certainly less busy on a smaller screen. That suits me down to the ground. I like to capture the photos, bang the Sd card straight into my Macbook Air, review them, edit and save the ones I like most and then back them up onto an external HDD. No internet connection needed.I think you will find Affinity excellent, and at that price it's less than I paid for the very first release. All my photographs are RAW, or RAW+JPEG, and the RAW facilities in Affinity are very good, and I can work directly with RAW files before developing them and then saving them in the Affinity .afphoto format for further editing, and subsequent conversion to JPG, PNG or any one of the other 10 formats offered. Another newer and useful thing in Affinity is a reasonably wide-ranging set of lens profiles.
I have previously used Lightroom and Photoshop, and have tried some others like ON1, but, like yourself, I wanted something non-subscription, non-cloud/online and reasonably priced, but powerful, and fortunately Affinity launched at the time I intended to make the change. Anyway, have fun with your choices.