Yep. Similarly, did I "need" those Kastle MX98's? Nope. Could've mounted up the vintage Dynamic VR17s and made due. But I wanted them, and I bought them. Guess what? I really like them.
Buying a light bike that may cost more than some people's car may seem silly to some or many, particularly when so much more can be gained through training. Here's the counterpoint to that, though. Sometimes the bike is the incentive to train hard and lose that weight. In my case, I spent a vast amount of money on a very light state of the art bike with a power meter. It was an incentive to train. As a result, I've lost nearly 60 lbs since I seriously started training a bit more than a year ago. I've lost 20 lbs this season. And I'm hoping I can drop another 15 lbs in the remainder of the season. Losing that weight has drastically changed my cycling. Where last year my ride notes state that I was disappointed with the number of folk passing me uphill but I caught them on the descents, I now regularly pass most of the cyclists uphill. I still can't outclimb the ultra-fit Boulder semi-pro folk, but I'm a reasonably descent cyclist now.
Will that make a better payoff to my cycling than the expensive bike did? Sure. But the bike also provided, in part, the incentive to train hard.