More demand might eventually result in more supply, but that can be a very slow reaction. If more people start flying, the airlines will initially just jack up prices for seats. If that increased demand is projected to be long term or keep growing, the airline might buy more planes to add routes, but that's a long and expensive process, and they're likely to do it just enough to keep prices high.
If more people are buying new cars, the dealers are going to tack on fees to increase their profits because they can. Eventually, the auto makers might increase production so that they can make more profit, and that increases supply could lower consumer prices.
If people suddenly decide to save their money and not fly as much or not buy new cars, there will be a glut of seats/cars, and the prices will drop as the sellers compete for the reduced number of buyers.
So that's the whole reason the Fed is raising interest rates to try and slow inflation. The thought is that if you have to pay more money to finance a house or a car, or to get a home improvement loan, you're less inclined to do those things, so there will be fewer buyers and more supply than demand, which will increase competition and reduce prices. It's been working.