Bitcoin is really something Unique (more than any NFT), although it is fungible.
Actually, since it's pseudo-anonymous, Bitcoin is not really (100%) fungible...
I will expand on this because the sooner we Bitcoin folk get our heads around this the better.
Not only is Bitcoin NOT fungible it is
ABSOLUTELY NOT fungible from a pure mathematical aspect. EVERY satoshi has a pedigree. You can trace it's origin all the way to the coinbase it was initially realized in. And you can see the trail of addresses it is passed through to wherever it currently rests.
Before you get all mad at me, and Batslap me... I am NOT making a case for a shitcoin. I am just being honest about a
feature of bitcoin that we need to come to grips with, and the sooner we do the better.
The FBI, for example seems to have figured this out.
https://bitcoinmagazine.com/markets/fbi-forms-new-bitcoin-unit-as-doj-taps-new-crypto-headBitcoin is a completely open book. This is a tradeoff that Satoshi realized the downside of fairly early as he talked about address reuse. And as we cheer the world waking up to what bitcoin is in the wake of the bank account seizures we also have to see that the satoshis donated to the protesters recently have mostly been flagged, and it will have created a challenge for the users to deal with.
So, there is the growing school of people that preach an amazingly difficult sort of privacy hygiene for Bitcoin, and it surprises me that these folks do not see that they are essentially just making their coins ready for a "list". We are already seeing exchanges treat these coins differently. Accounts get closed, and transactions are refused. Plus the trouble to which one must go to keep their Bitcoin private is beyond the skill level of even very technically adept people. It is unrealistic to "make every transaction a coinjoin" currently. This is ON TOP of the fact that it also might be a bad idea.
And frankly the idea that we can add enough privacy features to bitcoin at this point is VERY dubious in my opinion. There are certainly some ways it can be done... BIP 47 is a HUGE improvement, and I hope we see that implemented more widely (currently only as PayNyms in Samourai), and layer 2+ can be built to be much more private. Liquid for example has some of Monero's mojo in it.
Anyway. I think this needs to be a much wider discussion in the Bitcoin community since we are already seeing government organizations use bitcoins transparency, and they are only going to get better at it.
Ultimately Bitcoin's fungibility is as good as we make it as the users. Do we care about what satoshis we are paid with? I think that is part of the answer... I just don't know how we all get there. It's an interesting problem.