Scarcity in itself doesn't create value though. You can have as little supply as you want, but if there is no demand, there won't be any value.
I'd argue that the thing that gives Bitcoin value is its brand name, its first mover advantage. Everyone has heard of Bitcoin, but almost no one has heard of, say, Ethereum or any other altcoin.
Compare Bitcoin to the thousands of shitcoins that are also scarce and have limited supply, but are worth (almost) nothing because they have no brand name. It's not that they are technically worse than Bitcoin, some may even be better than Bitcoin with some cool features. Yet they aren't more valuable than it. Simply because Bitcoin was the first.
Agree. Bitcoin has obtained its value mostly because of its branding recognition within the mainstream world. It's the first coin it comes into mind when anyone joins the world of crypto. It could have an extremely limited supply, but without demand, it'll be a worthless cryptocurrency across the market. I've seen some cryptocurrencies that are pretty undervalued considering their level of scarcity across the market. Litecoin is a good example of a coin that's much scarcer than most popular coins on the market (like Ethereum) but it's extremely undervalued these days. The only coin I believe that it retains its value over time is 42 coin. Right now, it's worth an average of $16,895 across the crypto market. This is odd for a coin that's not well-known within the crypto industry.
As for Bitcoin, it's hoped that each block reward halving would contribute towards its price in the long term. But the definitive indicator of its value, would be how much demand it experiences within the market. If people aren't deeply interested in Bitcoin, then I see no reason why it should increase in price for the foreseeable future. Just my thoughts