Indeed.
Would you say USD in a bank account is fungible? I am of the opinion that the answer is no, because of the permissioned nature of that system, but also because of the lack of privacy and anonymity.
As it exists today, I think the same is true of sats. Of course, unlike the above, Bitcoin is permissionless (i.e, one is not hostage to a third party when it comes to sending or receiving) .. but the transparency really screws the privacy and anonymity up.
And that's what in turn makes sats be valued differently than other sats by some/many people. Powerful people with a dildonic desire to dominate and control others.
It's all fun and games until one wants to pay for a very expensive item (car, house, etc) and the act of obfuscation (coinjoin, etc) comes up.
Then, because the system is transparent by default, any attempts at gaining privacy are seen as suspect.
Again, this is why in Bitcoin you see efforts to marginalize coinjoins, mixers, etc, whereas with Monero it's the asset itself that's under attack (delistings) - precisely because no useful distinction can be made, and therefore they cannot censor what they don't see; so they go for an outright ban.
And yes, in either case we can (and arguably should) tell them where to shove it and keep coinjoining and (at least in my case) using Monero. As you can probably tell, I have zero issues with any attempt to gain privacy and preserving anonymity.
Those can come with challenges (bad people do exist), but I see the collateral damage of having everything tracked as much more impactul.
And look, it's not like I'm bashing BTC here. But if it is to improve, it is helpful to acknowledge where the weak points are.
And to me, as a regular user of crypto for many years, it's glaringly obvious that privacy-wise, Bitcoin is a bit of a nightmare.
And the situation as it is now constantly pushes towards more control, even if the network ispermissionless, because the control freaks have grown used to doing blockchain surveillance en mass, without warrants, at their leisure.
Add to that the fact that all the transparency creates myriad ways to discriminate based on many different attributes. It is precisely that which erodes fungibility.
X(anon) transfered Y to Z(anon) - not much chance to discriminate there. Like physical cash, except it does leave an encrypted trail behind, which while not as good as no trail, at least when it comes to privacy, seems much better than a completely transparent and eternal trail.
Anyway my man, perhaps we will continue to disagree and that is fine, it was a good back and forth. In the end I can assure you that we both want Bitcoin to succeed no matter what else.