Nobody is disputing that fresh garlic is a wonderful, magical ingredient. I’ve been growing garlic since the 1990s, at a rate of about 400 bulbs per year, so I’m quite familiar with its charms. It’s a gustatory chameleon that’s at once spice and vegetable, with a variety of flavors to give. When fresh garlic is added to a dish early and allowed to cook, its raw bite is replaced by sweetness and mild, permeating pungency. If added at the end of cooking, that same fresh garlic contributes piercing fireworks.
But garlic powder acts like glue behind glitter, adding a subtle fullness of flavor that may be more difficult to detect, but nonetheless makes the meal taste better. Like MSG, garlic powder may not be specifically discernable, but in a side-by-side comparison, the otherwise identical dish with added garlic powder will win."