its just example what can happen with small supply coins when there is huge demand and no body sell them and there is max supply compare to diamonds and gold, its fucking surge the price to astronomical number, its happen over the history in other verticals....
for example there was few rare diamonds which the price was around 80 million dollars per diamond, the demand grow for them and no body was sell them so the price surge to 150 million dollar per diamond , so after some time was founded bunch of this diamond compare to few , the price fell to 60 miilion per diamond.
its a game of supply and demand and if supply is very low and demand is very huge and no body sell its surge the price of the supply to astronomical number.
this kind of effect cannot happen with projects with billions of coins because if the supply to much big it lose value over time and demand will never will be more then the supply in projects with billion of coins.
I actually don't entirely agree with this section of your post.
While it is true and universally recognized that supply and demand is what ultimately shapes the market clearing price, there is no indication (or rather, guarantee) that demand for BTC will grow at such an astronomical rate over the next few years. Also, your comparison of BTC to rare diamonds doesn't make the most sense either.
Furthermore, in terms of your statement about supply, that's not necessarily true either. It really doesn't matter whether bitcoin's supply is 21 million, 2.1 million, or 210,000. An increase in demand should still result in the same percentage gain, if you get what I'm saying.
this effect will start to work when people dont need to convert crypto to fiat money and use it directly
This part, I definitely agree with.
Once merchants start adopting BTC on a large scale, I think that there will be significantly less downward pressure on BTC as people are capable of now fulfilling their needs without needing to move out of this asset, leading to less supply.
Another point that needs to be mentioned is the long term depreciating nature of fiat currencies, which means that even if demand of BTC stays relatively the same, assuming all else equal, there should be an increase in nominal BTC prices - since it has a capped supply and therefore is a long term store of value. However, when will hyperinflation come, nobody knows.