Let's say SSDs have an annualized failure rate of 1%. (The real figures are from 0.5% for more reliable ones, 1.5% for less reliable ones). The annualized failure rate for HDDs is a bit higher, but let's give it 1% anyway.

Over 40 years (even with changing disks, upgrading PCs, etc.), the chances of you ending up with your data intact is 0.99^40=0.67. May not seem too bad, but this is just a hardware failure of your main drive we're talking about. When you factor in all the other types of screwups that happen, the annualized failure rate will skyrocket.

So a more conservative version of this quote is that a 20-year old today is very likely to experience data loss over his lifetime.

Thankfully with cloud being ubiquitous at least photos are given one copy in the cloud, but IMO even that is risky. People have different appetites for risk, and that's OK. But over the last 20 years the all of our data has become pretty important. I don't know how many people could stomach the loss of important documents, photos, etc.

It’s because they all use cloud services these days which the tech companies manage backups for them. The only risk is getting locked out or banned which is far less common than hard drive failures or malware back in the day.

It’s still vitally important if you are self hosting your data.

> 99% of people don't backup

This depends on your viewpoint. Using gmail for example is an implicit backup of your e-mails. Uploading your pictures to Facebook the same. The move from local, private compute and storage to the cloud solved this issue for many to a degree that it is now less important.

I think this is more a quote for engineers