There are some brands of bicycles that can cost more than the down payment on a car. Why? Surely making a bike lightweight and reliable isn’t so difficult that it warrants that price? Is it just the brand name or maybe it has to do with customization options?
For some more extreme riders, they need bikes that are designed way stronger than any average bike. Imagine jumping a 50 foot ramp on a common bicycle, you’ll straight up break the frame in half.
I had met a retired rider from https://m.pinkbike.com/ and had a chance to ride his ~$8000 bicycle, that thing was built like a friggin’ tank with some of the most advanced mechanical features I’ve ever seen, including adjustable hydraulic shocks.
As far as lightweight, that bike was anything but lightweight, it was rather heavy actually, but when frame and fork strength is way more important, that’s just a necessary tradeoff for safety in extreme riding.