Price gouging is a real thing and "the price of things is higher than it usually is due to increased demand and reduced supply" is actually part of it's definition. I.e. price gouging isn't a replacement for the supply/demand model rather a description in certain extreme cases of said model, often regulated cases depending on the jurisdiction.

Traditionally it referred to traditional survival items though, not just any item.

Increased demand doesn’t increase prices on its own. The seller also has to Choose to sell at the higher price.