To me, there are lots of important shots to be made in a game. Break Shots, Rail Shots, Stop Shots, Draw Shots, Safeties & even more. Lacking the ability to perform these shots well, does make a difference in the end result, sometimes.
In the top levels, break shots were something you had, have or don't have. With their exceedingly good shot making & their exceedingly good safety play, They could run out from anywhere & get of trouble from anywhere, hence their attitude toward the Break Shot.
Then along comes a young man with the patience & determination to learn the Break Shot & can perform it like a machine. This scenario plays out a lot & the others have become finishers behind the machine called Shane Van Boening. He doesn't win everything, nobody can, but he strikes fear in their boots, because he's got a good Break Shot & a game to match.
Is the Break Shot important, make up your own mind. He thinks so...
The Break Shot is an advantage or a disadvantage, it's your choice.