Remember the dot-com bubble? Remember e.g. InfoSpace? In March 2000 this stock reached a price $1,305 per share, but by April 2001 its price had crashed down to $22 a share.
According to your logic: People were paying over $1,305 per share for something that they're not actually planning on ever using. That makes perfect sense.
I may be going out on a limb here, but it's entirely possible that at least some of the people who payed $1,305 for a share of InfoSpace did in fact plan on
using these shares to receive the huge dividends that these new Internet companies seemed to be promising. Of course, the huge dividends never materialised, but that's the risk investors take when investing in highly speculative ventures. Most people who invest money in a thing do so with the intention of using that investment to make even more money.
The people who bought overpriced tulips planned to use their tulips to make a profit by selling them to greater fools. Not the most sensible use for tulips, and certainly not sustainable, as they found out the hard way, but it is a use nonetheless.
Do you know how markets work? A thing is worth what someone else is willing to pay for it.
Yes. And why are people willing to pay for things? Because they want to
use it for something!
You can't seriously be asking what will happen to the value of bitcoin when a particular event happens after people have already stopped using it and aren't ever going to use it.
If nobody uses Bitcoin, its value is zero, regardless of all other factors. Bitcoin has value
only because people are, in fact, using it right now. Some are using it to buy things and some are using it as a speculative investment, but it doesn't matter
what they're using it for; as long as Bitcoin is useful for
something, it has value.