The issue in real time was years of the show runners promising over and over and over that "every mystery will be answered, and there will be no loose ends after the finale, and we already know what the end is going to be, just trust us".
People were extremely hyped because dozens and dozens of mysteries were generated over the seasons, so to tie them all up would be incredibly impressive.
Unfortunately it was blatantly unrealistic for that to happen, and there are several examples of the writers not having a clear direction and just stringing the audience along by creating more mysteries than they could possibly solve to add "suspense".
Two decades later it's sort of a different experience watching the show on its own terms.
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