Bitcoin fungibility is only an issue in the first place because centralized blockchain analysis companies have succeed in convincing a bunch of people that some coins are tainted based on completely arbitrary and provably false assumptions. For Wasabi to claim they have solved this issue, when they are complicit in the very existence of it, is laughable. They would do far more to help bitcoin fungibility by not directly paying blockchain analysis companies to label your coins as tainted in the first place.
Dollar or euro or yen bills are fungible by definition, bitcoin is also fungible, as you mentioned there is no problem here to be fixed, if somebody is refusing to acknowledge that your one dollar bill is a one dollar bill that's not the problem of the bill itself and it can't be solved unless you slap the guy till it stops seeing traces of cocaine on your bill.
If the fungibility of coins would be a problem, Wasabi is technically not "solving" it, all it does is circumvent it.
Also, I don't understand why they are mixing in this article a lot the notions of privacy and fungibility..
If I were to exchange coins with o_e_l_e_o we (probably!

) wouldn't care much about the history of those coins nor would we demand KYC from each other, thus our privacy is safe, and the fungibility is not a problem, besides we can safely use a mixer to erase the links between our coins and wallets. If you deal with CEX then your privacy is gone so what is left of it?
The rest of the article is irrelevant for me.
I would like to highlight that despite these big claims like
'state-of-the-art Bitcoin fungibility solution.', Wasabi unfortunately is one of the businesses that, as I mentioned above,
hurts Bitcoin fungibility by
allowing themselves to blacklist certain UTXOs, which in my book
is the exact definition of the Bitcoin fungibility problem.
I liked nopara73 take on that, he basically sad that only coins coming out are nonfungible, so their coins are better than your coins, but that's a fungibility issue, it's something they are "fixing". Again, you still have your privacy, or how he put it, but you don't have the fungibility, which by all standards, it's quite useless.