If you compare Apple’s PE ratio to the S&P 500 and tech companies in particular, you’ll find that the market is already expecting relatively low growth.
Capital has not become cheaper. On the contrary, interest rates are on the way up.
But I don't think it's growth expectations that are driving stock prices either. It feels more like investors shudder at the thought of owning any of the alternatives to US blue chips.
Now their PE is 18, so the market is expecting Apple to grow a lot faster in the next 5 years than it did in the last 5 years.
https://ycharts.com/companies/AAPL/pe_ratio
We'll see if the market gets it right this time or at least not as horribly wrong as in the past.