What would we ever do without your powers of observation? Did you only just reach this conclusion now, after so many hacks and thefts of crypto assets have taken place? Or were you perfectly "at ease" regarding your own assets for all those years prior?

It is better to divide your holdings into several (more) parts and store them using various methods, such as exchanges, mobile wallets, and online services, rather than relying solely on one or two hardware wallets. Should allocate specific portions of your portfolio to each storage method based on the potential risks involved. This is what is known as risk diversification.

I wouldn’t go so far as to "revere" airgapped hardware wallets as being super reliable, there’s no telling what vulnerabilities might be lurking within them (what if they contain a flaw similar to the one found in Coldcard?).

Consider this one of the reasons why investing in cryptocurrencies is considered risky.

Or perhaps it is because the very nature of cryptocurrencies lies in the irreversibility of transactions, where the actual owner is simply the person who holds the keys? In other words, what is the point of investigations if it is impossible to identify the perpetrator (given the privacy and confidentiality inherent in cryptocurrencies) let alone recover what has been stolen?

There is no such thing as a perfect solution (one that guarantees 100% security). However, it is possible to combine various solutions - in this case, different methods for storing cryptocurrencies.