I'm really having trouble understanding how a company with the best selling car on the entire planet (more Model Ys sold than Toyota Corollas or RAV4s in 2023) can be accused of "under-delivering".
Under-delivering is always compared to your promises. And they significantly over-promise, and, thus, consistently under-deliver. Especially at the company level - look at the Cybertruck and electric trucks - way over schedule, under powered, and under-delivering on every single metric they claimed originally. FSD is the other major example - which has been "fully autonomous safer than a human driver by the end of this year" for 5+ years already, and is none of those things in practice.
Also, while the sales are nothing to scoff at for such an expensive car, Tesla is still a small player in the world car market. Toyota sells more cars in the USA alone than Tesla sells worldwide (but much cheaper).
No other manufacturer comes close to Tesla's autonomy so it's not like people are gonna go and choose a competitor over that. Cybertruck, likewise, is amazing, so it really doesn't matter what the promise was as long as the product remains the best on the market, and sells. And their cars sell. Really well.
Also, while the sales are nothing to scoff at for such an expensive car, Tesla is still a small player in the world car market. Toyota sells more cars in the USA alone than Tesla sells worldwide (but much cheaper).