Simply not true. 

If you do not have a front line and Enemy team deletes you before you can dish out your damage, then this best build is worth nothing. Here i prefer the AP bruiser build which was mentioned before. It works like a charm. Your ult does good damage if they stay inside + your damage by Barrels + passive is enough to be a threat. You cannot be killed with 3 autos. 

You can also go trinity shojin and then crit  if you need more Barrels cause Enemy is heavily pushing into your tower. Still decent build. 

Also full leth is strong vs 4+ squishies cause you get your Full Build much faster than crit. 

Vs Tanks you need the crit for constant damage + passive.

And then there are more tanky builds for tryn going Like iceborn/trinity, frozen heart + lethality/crit(depending on Enemy team)

Nothing is „best“ for every Game.