I understand where your coming from. Investments do not just produce monetary benefits though. FSD is more than just a feature. Its software that continues to expand upon its features and capabilities and as it does so will increase in value.Paying more money for a feature on a depreciating, mass production car has *never* been an investment.
We feel like it is a good decision that will add to the resale of the vehicle and provide us additional features during ownership. I see benefit from having use of the features and access to new features as well.
Some folks may not see the benefit of FSD and that's fine too. To each their own.