I know why the capital class loves MRR I'm just mad that OTC is ignored.
One-shot option seems attractive, but the desktop (MacOS at least) app market is actually so niche that the SAM is somewhere in the low thousands. So, if I would offer a one-time 100$ app, I'd have 100k$ before taxes. And for that revenue, there's developing, marketing, plus support and maintenance. So to match a dev's salary, I'd need to make 2-3 successful apps a year, that I'd also have to maintain for a long time.
I think maybe there's a mid-ground with buy forever, 1 year updates, so people get the product they paid for, and if they want updates or support the development they can re-buy, however I'm yet to hear opinions on this model.
As far as desktop software is concerned, I think this a commonly accepted approach. Sublime Text is probably the most notable example.
Personally I like the model, as long as old versions stay truly static and don't get enshittification updates. It aligns incentives on feature development far better than subscription models: if you make genuine improvements you get recurring sales, if you don't then existing users will just stay on the old version. And existing users are protected from features or UI changes they disagree with