I think your comments are reasonable, though I think if you look at it from a broader perspective you'll be able to understand why it's more complex than that.
First of all I'd like to say that I only really believe in bitcoin. It is the only one with a
fair launch, no pre-mine or initial distribution to founders. I think digital scarcity is a once-in-a-lifetime discovery that
can't be copied.. Also very importantly, bitcoin has no leader, no central point of failure, is truly decentralized and is the only one that can really
stand state-level attacks..
While in this moment we have a lot of random coins going up in price, I'd consider that more akin to gambling with something that has no fundamentals. It's easy to have things doing good when everything is going well, but can any of those coins really stand state-level attacks, enemies with billions of dollars trying to disrupt it from within? IMO they can't, and they won't. They are imo failed experiments in action, like alternatives to TCP/IP which have been completely forgotten, almost erased from the history books.
Also, I don't believe in trading, I believe in buying and holding till the old corrupted system has been toppled over. You are completely right that trading provides no goods and services.
That being said, regarding where the value comes from if you buy bitcoin for cheap and it raises in price, lets think about it for a moment. How does something become money ? IF bitcoin was to become true money, how else would it happen other than a volatile path upwards in value as adoption grows, before it stabilizes at the top?
Think of gold for example, it had thousands of years to become globally accepted as money. What about the first person that found gold, imagine him trying to sell it to others and people being like: "are you nuts, why would I trade my cow for this shiny rock?". At first it was worth nothing, over time it probably had ups and downs based on people believing it would work out or not. It took many many iterations of social interactions related to gold before it stabilized in value. Price discovery is a dynamic process.
Also, consider that the value increasing is not coming out of thin air, it is being drained from other stores of value. Sound money drives out unsound money, as
monetary systems converge to one. Simple supply and demand at play will show that the more people want bitcoin, the more it raises in price, while at the same time people are selling other assets or currencies to buy bitcoin which means lowering of prices of these other assets.
This probably deserves its own thread but I just wanted to answer your concerns here