Bitcoin's value is in the brand. You can generate a clone coin but the network adoption (i.e. merchants, users others) won't be there. That is why most of the cryptocurrencies clones are worthless or worth much less.
You cannot go to a store and pay with a gold bar, but I can assure, it has significant value. The value of anything, whether it be a share of Amazon or a pack of cigarette is exactly what another person/entity would pay for it given the time and location. A pack of cigarette has a higher value in the prison than in the outside world.
Bitcoin's value according to the market is ~$4,000. It's not an opinion. If you have one, you can sell it for that much and if you don't have one, that's what it will cost you to acquire one. Other cryptocurrencies have their own market price.
No-one has disputed anything you said. I was replying to @HolyGrailSeeker saying Bitcoin will go to 20k and then 1 million. Ridiculous. I hope he has literally sold everything he has and bought bitcoin, I mean it's a sure thing according to him.
You can't use Bitcoin almost anywhere. Listing a few businesses here and there don't make it an usable currency. I'm talking about Visa or cash equivalence. Therefore a competitor could easily destroy them. They are not like Amazon at all.
