Basiclly have they lost that "eerie" sensation and momentum. When Obito was Tobi, he was awesome and seemed pretty dangerous even when he was unmasked for a little bit. But now he talks too much and seems like a regular "villian" whose nothing special.
Madara was oftw when he returned and his techniques were OP. When he slaughtered the 5 kages he seemed unstoppable but know all that momentum seems to be gone. Hes just an observer for now.
They dont fell like villains at all anymore because of the Juubi(which was disappointing and failed to live up to the hype).