You guys posting these 150-300dmg screenshots, which are nice, but what are you actually trying to show? Haplo pretty much showed everyone how a buffed Sword Saint can easily outdamage everyone, my designated tank SS (Monk1/Pal2/SSx) have his saves at +30, AC 70+, and a few days ago killed Ithuliak during the first round at lvl 15 (didn't even have greater vital strike at that point!) And can pull these things off basically anytime, all the while tanking both magic and physical.
Thank you for the praise.
Yeah, Sword Saints are the best tanks in the game and, at the same time, also heavy damage-dealers and boss (single target) killers (need some luck with crits for it to actually be 1HKO, though).
At the same time, other classes bring other great stuff to the table. Casters can Crowd Control and also, if built properly, one-shot crowds, like Shadenaut has shown.
Vital Strike is cool and provides some cool vow moments when the stars align and you crit at the right time, but its certainly not the best Standard action a character can make.
This is particularly apparent in the Turn Based mod, where Standard actions really matter (and full attacks matter less - unless ranged).
Many spells can often be more potent. Against a nice group, Great Cleave can be very nice. Kineticist Blade Whirlwind is made of pure win.
Lastly barbarian Pounce Charge can often be a more damaging option.
Plus there's the whole support and party play angle other classes bring to the table (like the Freebooter or Bard).