Yes they are. But they are still far more interesting becouse they are exclusivly designed for 1 difficulty only. Mythic will never be interesting becouse it is still same content what playera clear in LFR. There is no new boss, no new lore. Nothing it is same content.
Yes becouse Blizzard also invated lot of players what never played vannila. And post like classic dungeons are way too easy are created by clueless players. They see lvl 15 players running lvl 10 dungeon completly outgeared while players are experienced raiders and they wonder why it looks easy.