A little clarification actually on "impossible". With impossible, think of it like mission impossible Its possible, but just very unlikely that you could clear that content, you would need ofcourse perfect positioning, teamplay and RNG luck etc and then maaaayb you might get that 'impossible' world first. Making a boss for example with enrage timer but make it physically impossible to clear. That is not fun or challenging because its pointless. But, just imagine that they put in a boss for example that with you need that last 100k dmg and lets say that is like 20 seconds worth of damage. Wouldn't you want to keep trying with your raid to see if you are able to squeeze that 100k dmg extra from the beginning of the fight. Maybe counting a bit that your raid gets the crit RNG on your side for example. I think those fights would be very thrilling for those top players to keep them busy until new content is out. In anyway, I DO think its better to still have something to clear. Then just having a dungeon on farm status. Pretty sure im not the only raider here who simply after years on end, is just bored of farming the dungeons over and over again until its your turn to have the complete set, while the challenge from the dungeon itself is long overdue.