While that's true, the final product is determined by other things, like the water, the presence of peat, the rye, the malting, the time in the barrel, the number of times the barrel has been used, and even the air in the cellar.
It's illegal for distilleries in the US to re-use barrels, so they go dismantled to Scotland where they are reassembled and then used roughly five more times. After that, they are chipped and used to smoke salmon, cheese, etc. Those frugal Scots don't let anything go to waste.
There was an article here many moons ago where somebody invented an express aging process for whiskey. They nuke it with microwaves, zap it with electricity, or sumfin.