Your friend is lucky. If he invested in altcoins, maybe that could be the altcoins era that is the time before 2017 when the rally for altcoins was very high. Coins like etheruem at that time were very cheap and ico scam was not that rampant.
Maybe he was part of those who bought bitcoin early like 8 -10 years ago when the price was still below $1k. He is worthy of commending if he actually saw the future from the risk he took because some people saw the opportunity but felt cryptocurrency investment was all fraud.
Perhaps those were the times were altcoin prices shoot up and those who came investing in it have experienced huge profits. But what is happening today is the ultimate opposite. Altcoins are no longer considered as rational investment so investors have no choice but to stick with bitcoin which holds the highest position in the crypto market. However, we can always diversify our investments which means we can also invest in stocks, real estate and gold aside from our bitcoin investment.