But I think holding it for 5–10 years will actually be profitable.
By putting aside some regular portion, just like fixed deposits used to be. It is a type of investment or opportunity to make a profit. "Buy low, sell high" is an asset that you hold for the long term, not something that you "buy when the market is up and sell when it's low".
There is no experience that I have found that for a period of 5 to 10 years people complain about losses.
Bitcoin price statistics always show an increasing graph so I would agree that Bitcoin is a profitable long-term asset both in terms of price returns and hedging.
The best way to invest in Bitcoin is not to force it but to be consistent every time.
The ups and downs of the market should not deter you because that is how the market works. When the market goes down in price, the amount will be different from the market price going up. Those who do that will not lose money.