Bitcoin is in demand as an investment with a potentially unbounded upside and almost no downside (right now).
Now that I think about it, it is more like a rare painting than gold. It has a well defined supply.
An art investor pays millions for a painting in expectation that in 10 (or so) years, someone will pay more.
So the type of people who invest in fine art are  starting to invest in Bitcoin.
Like fine art, it has no intrinsic value.

Now, the downside seems to be extremely limited because of all of the new money flowing into bitcoin.
This is money from very sophisticated investors.

What is the upside?
Unknown.
People who should expect to get rich in 1 or 2 years will probably be disappointed.

Now is not the time to sell though.