The problem with the Night Warrior was that this great power that was causing her to implode still wasn’t enough to absolutely thrash Sylvanas. In fact they both fought almost to a sandstill until Sylvanas poofed away and Tyrande caught her from behind completely surprising her.
The issue is presentation, then there is the whole, nope revenge is wrong, its self destructive but only when Alliance/Night Elves do it. Baine can go on his murder spree in Dragonflight. Thats fine. Its ok! But Tyrande? Alliance? No can’t have that! thats wrong.
We got to find reasons why Sylvanas is a vicitim in a single patch after a decade of villainy, got to depower tyrande after doing nothing with it and have another trial. Because they are just so much fun.
They weren’t trying to tell a good story. The mission was to make Sylvanas look cool to hype for a raid and then save her from death because Horde needs its characters. She is off in hell until next expansion. Probably…