Dooku, Kenobi, Mace and Yoda would all hold up to the old masters but it's because they literally trained themselves in the old styles. Dooku openly advocated for going back to basics especially with the impending return of the Sith, but he was brushed off.
That's the irony, isn't it? Mace and Yoda, as the greatest Jedi of the post-Ruusan Order, while also holding the top posts* in the entire Order, trained themselves in the ways of the pre-Ruusan Order...and yet staunchly upheld the post-Ruusan standard for the rest of the Order. In other words, they should have seen how...fallen, the Order was, and yet they refused to do anything about it.
*Mace was the Master of the Order, while Yoda was the Grand Master.
Essentially, Vader is a terrible Sith Apprentice but a very good attack dog and trophy of Sidious' destruction of the Jedi. The big question is... did Sidious want that or not?
In the EU, as others have pointed out, that was all he was ever meant to be.
In Disney, though...this is actually one of the better changes made by Disney. That is, Sidious treated him as an actual apprentice, with Vader's lack of ambition actually annoying the Emperor. The Emperor even called him out on it in a very backhanded way, after the Battle of Yavin IV. When Vader insisted on still being the Chosen One, Sidious Force Choked him while mocking that that way of thinking shows he's still a slave, clinging to his chains instead of thinking of breaking them like a Sith ought to do. Slave to the Jedi, slave to the Force, slave to Sidious, leading to Sidious' contempt.
Vader's suit was actually top of the line at the very end of the Clone Wars, and was only outdated by the time of the films
because Vader refused to upgrade it. Hell, Sidious explicitly told Vader
not to see it as a prison, but as a hurdle to be overcome, and even encouraged him to upgrade his suit as he pleased. That Vader did not speaks more about Vader than it did about the Emperor.
But as shown in comics' climax, when Vader's attempt to build a power base gets outed by Aphra to the Emperor, the Emperor actually just takes it in stride, and even even congratulates Vader. Vader had broken the next link in his chains, and was finally acting like a proper Sith Apprentice. Now, all he has to do is kill Aphra as a test of loyalty, if framed as a 'gift' from the Emperor, and everything was dandy.
Disney Sidious wouldn't have minded if Vader killed him and took his place. Disappointing, perhaps, but if Vader can overcome all his countermeasures and contingencies and become Dark Lord of the Sith...well, that is simply the Way of the Sith. The Master has become redundant, and so must be replaced by his Apprentice, who becomes the new Master, as mandated by the Rule of Two as set forth by Darth Bane.
