People who invest without leverage will win someday, because those people holds real coin or crypto.
And, those who trades on binance or bybit with leverage will get liquidated. Just like forex!!
Investing and holding is really profitable like you rightly said but you much know what you are investing on if you want to make real profits. If you talk about investing in bitcoin, then you are on the right track that makes your investment get better with time. But if your investment is to a shitcoin such as we have littered in CMC and Coingecko, then you are setting yourself up to be roasted and the longer you hold, the more your money tends to zero. So be careful of what you invest in and hold because not everything is worth the investment.
Bitcoin will be the best option to invest especially if you hodl for a long term. He can focus in Bitcoin and leave the altcoin while he use Bitcoin as his main investment. That will give him a big profit if he can accumulate Bitcoin using DCA.
If he want to invest in altcoin, he really need to be careful because a shitcoin are too many now. He may pick a wrong coin for his investment and make him lose the money. Not altcoin can work well for a long term because the market will delist the coin with no use. So it is why we need to pay attention to Bitcoin more than the other coins and accumulating it for a long term investment.