But the raids are accessible, there are no attunements anymore, it's easier to gear up a new player (it's less rng related), you don't have to farm for flasks, pots , elixirs and enchants for too long.
What else do you want? Accessibility is there. You can enter the dungeon, you can tackle the bosses. If your guild fails then, you have to spend more time developing it, you have to form a team, that works together, that sticks together. Teach lesser players how to play, let them discuss with more experienced ones.
That's how you kill bosses, by letting people care for their team, not filthy epics. This is wat differentiates wow from say, diablo. That you have a persistent pool of people to play with, people you CARE about.
Sadly, if you cannot develop such spirit, every raid you will ever do will be doomed by boredom, selfishness and greed.