You have to discipline yourself within an art and hack away the unessential, when a sculpture sculpts, does he add on more? No, he keeps hacking away until the true nature of the sculpture is revealed.
That sounds logic at first glance, but in reality it isn't. By hacking away everything unessential in martial arts you will also lose the expectation of the unessential from your opponent and thereby can easier be surprised by any non-standard attack. And you give up any surprising attacks yourself. If you know the essentials and your opponent knows the essentials you equalize each other, but if one of you knows some unessentials stuff in addition, he's going to have the edge.
The problem with most so called "traditional martial arts" or better said with a lot of their practitioners is that they are too much in love with the unessentials (i.e. flashy moves) and have too much of a focus on that in their training.
The "art" for good training is to find the right balance. Yes, you should have the focus on the essentials and use the majority of your training on these, BUT you should not get a tunnel vision and only train the essentials, but always use a small amount of time to look beyond the essentials so you will be prepared for what could come else and also to have a "surprise" attack in your own arsenal.
Its nice in theory to think that we are there but the top trainers in sports like kickboxing and boxing are vastly more refined due to the years of work put in before them. MMA is not at that level which is why guys like GSP still seek out the likes of Freddie Roach. It will be a long time before MMA is at the level many fans would like to believe the sport has reached.
I would go even further and say it will never reach that "final" level. I think fighting and MMA is too complex for fighters to really master all aspects of it. So there will always be an evolution or at least a change of focus.
The other problem lies in that different physical traits and abilities as well as the other skills they possess as a fighter. Brock Lesnar is never gonna be throwing head kicks, his body type is better suited to traditional boxing. We will see mma striking develop in its own right but they will always remain ties to the traditional arts and they will use those to refine and perfect them on a fighter by fighter level.
That is very true also.