You are likely correct that there is a sliding scale when it comes to fungibility, and I think that most free market types are going to perceive the most value in bitcoin being associated with greater levels of fungibility... so yeah, you are right that lesser fungibility may maintain some value, but the amount of decrease in value may be a lot greater than what you seem to be projecting it to be. For example if confidence is lost because coins get blacklisted, then surely that seems problematic to me if it is allowed to occur. So if any 3rd party such as coinbase or fed government tries to label coins, then there would likely be some effort by the bitcoin community to either not use their services or to move coins to other location and clean them of their blacklisting.
I think there is an argument to be made that zero fungibility may cause an increase in value as governments would accept and regulate such a state. I can see a scenario where your
address will be issued and monitored. If this becomes a future scenario then TPTB would actually cause an increase in the value as institutional investment would increase exponentially. and Ironically BTC would become the exact opposite of what it was intended yet as a side effect continue to make early adopters rich.
there it is...perfect timing

I almost gave you a congrats merit for this.

Also glad there was a screenshot as I didn't know you had laughing man avatar that alone is merit worthly.

I'm with you I didn't have the heart to ruin his moment.