Others, probably most Tesla owners, will have a different view but to me, FSD in its current state is a cool automotive feature, for lack of a better term. Like a 750 hp engine, or driver-adjustable dampers, or an audio system with 19 speakers. It's fun to play with it and experience it in operation, but it doesn't truly fulfill a need.
For example: Say you are a disabled person who needs a car that can drive them point-to-point without any interaction. You need it to open the garage door, back out of the driveway, drive to the pharmacy as instructed without any interruptions and with zero mistakes, drop you at the door, and go find a parking place and insert the car in it. Tesla FSD can't currently do that, but it gets closer with every update.
As for being one of Musk's lab rats, indeed. When I purchased FSD, I paid cash up front and waited many months for the feature to be activated in beta form, and then I had to demonstrate that i was a safe enough driver to use it, even though I had already paid for it. And yes, it did occur to me that I had in effect loaned thousands of dollars to the wealthiest man in the world and he was riding the float. That impression grew stronger as "soon" turned out to be not as "soon" as suggested.
There are people (nerds) who enjoy being beta testers of every new technological advance, for example in PCs and software. In the early days of the PC I was one of them, but I quickly got over it. Tesla FSD was significant enough to me to jump in early to see what it was about. If you are of a similar technical bent, you will find FSD worth the cost. But if not, it's not really value for the money. If you want a Tesla but want to save money, it's the first thing to drop off the option list. (That and the white interior.) A base Tesla 3 without FSD at $42K USD is actually a lot of car for the money.