Index funds have allowed me to not have to save for retirement anymore (have enough based on FV calc), and yes buying the FAANG stocks 6 years ago would have yielded much larger returns, but could also have yielded losses if they went the way of Exxon.
Definitely. Not saying don't put money in ETFs but the returns aren't as fast and you have to earn a good salary to do so.
However adding some money into the market leaders would be a wise idea IMO. I.e. TSLA and AAPL. Since you are in the ETF ($SPY) for now then you are already invested in AAPL as it's the largest portion of it so adding TSLA which is going to be $5,000 in a decade would be wise.
Index funds have allowed me to not have to save for retirement anymore (have enough based on FV calc), and yes buying the FAANG stocks 6 years ago would have yielded much larger returns, but could also have yielded losses if they went the way of Exxon.