What happens if someone builds their life or company on an .eth domain and loses the key?

I know a few people and also a few companies which would go completely down the drain if they lose the domain they built up over the years and often decades. Usually some .com domain which is heavily dependent upon search engine traffic.

With .eth domains, is the loss of the private key a non-recoverable incident?

Securely storing a single key seems like a hard task to accomplish. Either it is: Very secure but also easy to lose. For example when the key is only store in the head of one person or only in one safe. Or: Hard to lose but not very secure. For example when it is in multiple safes or in the heads of multiple people. Now it is hard to lose but more likely that someone malicious gains access and transfers the domain away.

What is the approach to this as we go forward and .eth domains become more important?