Because Tesla keeps claiming they'll have full autonomy "next year", year after year.
In 2016 Tesla claimed every Tesla car being produced had "the hardware needed for full self-driving capability at a safety level substantially greater than that of a human driver". That was a lie: https://web.archive.org/web/20161020091022/https://tesla.com...
By the end of 2020 there were supposed to be 1 million Tesla robotaxis on the road. That was also a lie: https://www.thedrive.com/news/38129/elon-musk-promised-1-mil...
Tesla sets its own benchmark and consistently fails to achieve it.