No, bitcoin does not need fungability to have value.
No. Bitcoin does need to be fungible if it wants to be money!
If it is not fungible people will start using another coin as money and bitcoin will lose its value!
Well the reason you are wrong is because you falsely conclude that ANY of bitcoins value today is because it "might" be as fungible as money in the future.
It 100% IS NOT as fungible as money today and never has been in the past.
I can assure you that bitcoin is not going to lose value on fungibility issues because it has always been as fungible as it has ever needed to be.