And yet those others weren’t able to accomplish anything with their machines.
It reminds me of people who say "the Vikings really discovered America centuries before Columbus"; however, the Vikings apparently didn't tell anybody.
I hadn’t heard of the steam-powered plane before! Interesting!
Similar inventions tend to come at the same time all over the place. It really comes down to a matter of luck and access to resources and funds.
...except be first to fly a powered heavier-than-air craft, which one of them was.
And truly, the Wright Flyer didn't accomplish much either, except to fly further and more reliably than any HTA craft had done before. I don't minimize this, it was a great accomplishment. The Wrights' accomplishment, really, was to demonstrate sufficient engineering and design skills to reliably repeat the experiment. All the developments in aircraft technology immediately following the flight at Kitty Hawk were based on their design, including the brothers' own work with Glenn Curtiss.
As with Columbus, The Wrights may well not have been the “first” but they were the first entrepreneurs to do it, the first significant doers of the deed, the first to make it commercially useful.