There's nothing wrong with using alternative solutions, but your critique of Emacs is mostly FUD and a repetition of cliches. Your two points are:
1. Org-mode (or Emacs?) is not completed, by which you imply it is in some kind of premature state that it's not ready to use. like some kind of "version 0.2 beta, use at your own risk". Nothing is further from the truth. Org-mode is currently on stable release 9.3.6. It has been tried and tested for many, many years and is widely used in its niche.
The fact that it is under active development is not a shortcoming, it's a plus. Unless you're arguing by analogy that you cannot use such software as "Chrome" or "TensorFlow" because they have not yet been completed.
2. RSI - I've heard this argument multiple times, and I believe that it actually might affect some people. I, for one, have been using Emacs for well over 20 years and have never had any problems along those lines. But for those who do experience issues, there are multiple solutions around that you might want to give a try. They range from remapping of some central keys to completely different ways of inputting commands, e.g., inspired by vim.
Don't get me wrong, you can user whatever you want. But if these two points are the only reason you shy away from giving org-mode a try, do not worry and don't let them stand in your way.