In many ways he's understating the problem. At least there used to be file formats to support, and files to lose. But how much of the data you interact with daily is even directly accessible to you? How much of it can you access when you're offline?

Take Slack. You can install it locally, but that doesn't matter, because it won't start without an internet connection, and its local storage is completely opaque. Compare this to a mail client, where everything is stored locally, indexed and searchable offline, and can be exported into a universal albeit messy MIME format, as well as imported into other accounts.

Of course this is necessary for the business model, the Slack free-plan event horizon wouldn't be effective if it only applied to which new data you can sync down... and if users only discovered this when e.g. moving to a new computer, they would quickly start to wonder why they can't just transfer the data they already have themselves.

With Google Drive, your 'docs' are just placeholders pointing to the cloud. You can export them individually to Word or print them to PDF, but it's a manual process, which you will likely only think of when it's too late.

For an example of how this can really matter: an acquaintance is embroiled in a legal dispute with an ex-employer. Thanks to Apple's sane implementation of IMAP Mail on iOS, she still has access to all her company communications there to use as evidence. Unlike on her PC, where she was just using webmail the entire time and has nothing.

The incentive in the cloud age is to create dysfunctional products that provide an illusion of permanence instead of the reality of tangibility. I expect this is only going to become a bigger problem over time.