Every single asset has tail risks and Bitcoin is no exception. So it’s true that there are valid arguments for why Bitcoin is a bad investment, despite its proven risk-adjusted return profile. There are many investors who see Bitcoin as valuable, and digital money as a hedge against currency devaluation.
In fact, the value of Bitcoin is unpredictable, which explains its volatility and inherent risk. It is, therefore, hard to make a good estimate on Bitcoin’s worth. Bitcoin investments are not a good idea for those who can’t afford to lose.
This is true for any investment, and most mainstream investments, like stocks, are in far worse shape and are likely being supported by central bank intervention. The only time when an unleveraged investment in Bitcoin would have produced losses was in late 2017. For the rest of Bitcoin's history, it has been an amazing investment.
Bitcoin could be a bad investment for those who don’t understand it. That being said, it has gone up consistently over the past decade, and there is no reason why it would stop now. Unless this is the absolute top of the Bitcoin market, it is still a great investment. Understand the markets, and how to best hold Bitcoin before you buy it.