Bitcoin started off as a currency in principle and there was even a concerted attempt to use it as such at one point. Various merchants got pestered into trying it out by libertarians across America, wearing their dad's ill-fitting suits and walking into random businesses to proselytize bitcoin. So there were some hip cafes and restaurants etc giving it a shot at one point and household name tech companies such as Microsoft were accepting it as a payment option too, which gave it a sense of legitimacy that advocates could point towards. Bitcoin could have taken off if it actually worked.
But there were several problems that sabotaged it's success. The most important I think was it's limited transaction rate, it could only handle a certain number of transactions per second which was well below what was required. It's something laughably tiny too, like 6 transactions per second. If you weren't blinded by greed or ideology then you could immediately see that it wasn't going to scale and was being launched prematurely, but the fanatics wouldn't hear a word of FUD (fear, uncertainty, doubt) against the holy creation of Saint Satoshi himself. This issue created a backlog of transactions that could last for over 24 hours at the height it's actual usage as a currency meaning that merchants weren't able to confirm payments in a timely fashion. This was the killer flaw that caused Bitcoin to wither on the vine but there were loads of other serious problems too.
From then on there was a lot of coping and seething, but not yet much dilating as this was back in 2014 iirc. The bitcoin advocates began to promise technological upgrades (always just on the horizon) to bitcoin which never actually materialized even after all these years. Then bag holders increasingly began to refer to Bitcoin as a "store of value", whereas I think it's more fair to describe it as a speculative asset. This was a massive pivot because at the time the libertarians were prophesizing that bitcoin would destroy the Federal Reserve, revolutionize the world economic system and grant Ron Paul his apotheosis to space emperor, but then they settled for "store of value" instead because they feared Bitcoin crashing to zero on the back of it's lack of actual utility.
I can't believe anybody besides the bag holders still has any faith in it after that.