Same thing with Tesla. I was going to buy shares before the pandemic, stating that they've been able to double in size every 4-5 years (in terms of factories built). However I was discouraged because people said that because this information is already known by market participants, that the growth is already priced into the stock. Making the price of each share potentially overvalued. Yet the price of each share has nearly tripled in value since then.
Also similar with sector ETFs. For example I've read that the cloud computing market will grow to 2 trillion by 2030 and was curious if it would be a good idea to buy cloud ETFs. Yet I still get the same response, that everything is already priced in. Yet Cloud ETFs like SKYY have still maintained a 20% CAGR for the past 10 years.
People like to list the efficient market hypothesis for why the price of a stock is never undervalued... But looking at the past 10 years of these stocks I just listed seems to prove that this isn't the case?