$15k this many years into it being "meh" feels almost criminal.
https://electrek.co/2022/03/24/tesla-spends-most-rd-least-ad...
Also, typically in any company revenue and PNL is attributed to the feature accumulating it and investment follows. It seems like a fairly rational bet.
According to statista.com:
2018 6.6%
2019 5.5%
2020 5%
2021 5%
This should give you an idea about your odds.
Not to say I live inside parent's head or anything of that sort, and they could be accurately remembering their intention and expectations at the time, but if I had to bet?
I bought it at $7k, knowing full well that I’d never likely see true FSD, but the features it added were worth it to me like navigation on autopilot, and lane changes on the highway. We figured that just those two were enough to spring for it, given we commuted a lot and did road trips a lot. So it was nice to have it take over every once in a while.
At $7k, it was pricey but not very out of line with other car companies upgrade packages.
I think the ROI really depends therefore on what price point it was got at (someone who got it at $3k probably likes it a lot more than someone who spent 10k), and what they were expecting out of it.
I think true FSD is a smoke and mirrors trick that Tesla will not achieve with their current sensor loadout.