You can't stop plagiarism, but you can change how you react to it. Simply posting on the same platform and hoping that you get the same amount of views (or more) is probably not going to work. Moving to another platform where you have more control, might.
If you knew that youtube had the most content but 90% of it was slop and that you had to question every video you watched, but that there was another platform where you could find less content but 90% of it was actually made by humans, which one would you pick?
We aren't there yet, far from it, but we will never get there is all you do is go "sloppers will slop, might as well stay here".