Bitcoins do not have value as a physical commodity like gold and are not widely accepted as legal tender like dollars.
Rather, Bitcoin appears to have value for the following reasons: It is popular.
In short, people accept and trade in Bitcoin because other people accept and trade in Bitcoin.
Everything has its value. As long as the recognized people are more valuable.
An antique, for example, is not really useful, but it is often valuable because there are many people who approve of it.
The same is true of bitcoins, which are now accepted by many people.
How this one is good though you tried to express it completely but there is difference between the bitcoin and antiques. Though the comparison was upto the market conspiring the OP's question.
So yeah, anything that has recognition or anything where people want to invest their own money (which is valuable ) gets the value of that much of money. For example, Lisa Painting, now what the use of that, despite the thing that it is just known for its mysterious smile and people want to have it because it is popular in the world and one of its kind! The end result is billion dollar painting.
In similar ways, bitcoin is crypto currency with at least some use for us. Its getting value because the demand for the same is growing day by day and people are putting huge investment into it. That why its getting value.