This is another difference that we often lose in the conversation: back in July of 2018 and into early 2019, there was a package called Enhanced Autopilot ("EAP") that contained all the currently available "autonomous" features of Tesla Autopilot, like TACC, autosteer, auto park, auto lane-change, and summon, as well as (in October of 2018) Navigate on Autopilot. Like many, I opted to purchase those features with my car.
At the same time, "Full Self-Driving Option/Capability" was a separate capability that promised "full autonomous door-to-door driving" and was "Coming Soon." It wasn't called Autosteer on City Streets and there wasn't really many details of what "full autonomous door-to-door driving" meant outside of Elon's public comments/tweets and all the speculative articles written around them. I don't think the take rate at that point was very good for "Full Self-Driving Capability" and like most, I opted not to pay for future speculative capabilities.
In February of 2019 in an ARK Invest interview, Elon stated that Tesla's Full Self Driving capability would be "feature complete" by the end of 2019. He clarified: "[m]eaning the car will be able to find you in a parking lot, pick you up and take you all the way to your destination without an intervention. This year. I would say I am of certain of that, that is not a question mark." Sometime after that, Tesla's order page for "Full Self-Driving Capability" was changed to "Coming later this year." Then, as 2019 autonomy day approached, it became apparent that the cars would need additional hardware to get FSD, and that only current FSD owners (and new car purchasers) would be able to get the hardware upgrades to support it (due to high demand and limited supply). Tesla then started monkeying with the price and Elon made several tweets/comments about how you would pay dearly for it later if you didn't buy it now. So a lot of current owners went ahead an forked out the additional money for the FSD package, since they would be available by the end of the year, in order to not pay the looming price increase promised by Elon.
Of course, during Autonomy Day 2019 (I would say the most outlandish and irresponsible of all of Elon/Tesla's promises around FSD capabilities and delivery dates), Elon doubled down on "Full level 5 autonomy by end of 2019" and estimated that by the middle of 2020, Tesla’s autonomous system will have improved to the point where drivers will not have to pay attention to the road. He also stated that "[w]e will have more than one million robotaxis on the road... A year from now, we’ll have over a million cars with full self-driving, software... everything... These cars will be Level 5 autonomy with no geofence, which is a fancy way of saying they will be capable of driving themselves anywhere on the planet, under all possible conditions, with no limitations." So after April 2019, I think any reasonable person would certainly understand why someone would say that they "relied" upon Elon's tweets and public comments in making their purchase decision for FSD.
Now, of course by early 2021, it was abundantly clear that neither Elon nor anyone at Tesla had any idea when Autosteer on City Streets (I will call it "FSD") would be available, despite Elon's continued prognostications on release dates, and I would go further to say that Elon didn't (and doesn't today) really have any idea what the actual capabilities of any "final" FSD product will look like. Surely, like any clear-minded engineer, he has long moved past the idea that any current Tesla vehicle will be driving around without a driver and operating as a "robotaxi," but exactly what "feature-complete" means for FSD and when it will be available to purchasers remains the subject of complete speculation. Basically, it will be done when Elon says it's done and it will contain the features/capabilities that it contains at that time. Does that mean L3? L4? Who knows? Certainly not Elon Musk.