These are server apps. This guy is talking about end user apps more.

Example: I prefer to run Google Earth desktop instead of Earth in a browser. It's faster, has more features and doesn't suck up as much memory.

I use Notepad++ instead of google docs for most note taking.

I use Kusto Explorer desktop instead of Azure Data Explorer.

Outlook desktop instead of OWA.

There are exceptions. The facebook messenger app I prefer in a browser, because, do I trust Facebook software to not scrape my screen and send it back to FB servers? I would much prefer it to live in my taskbar as a discrete app otherwise.

You're taking applications that are pretty inherently network-connected, like chat and sync. Yes, those make very little sense without a server. Although syncthing in particular will work just fine actually.

But a lot of things don't require internet connectivity at all, not inherently. They largely stay on one device and that's fine. If they're to be shared between people or devices, very often attaching them to an email is better than "share this link with your friends (all they'll have to do to see it is sign up for our service so Growth can report those sweet sweet activations)"

Unfortunately as far as email is concerned this is not so true anymore. Many years ago I used to do as you described but eventually switched to hosted services due to the likelihood of any messages being sent from said self-hosted server being flagged as spam in the best case, or never received in the worst case as you'll receive an undeliverable message due to the sender requirements of many organizations.

As with most nice things the bad actors (spam, phishing, etc.) in society will abuse things to the point that we can no longer have them.

I've self-hosted my personal email for 25+ years, at a variety of ISP's and multiple IP's over the years. It's not fully automatic, not cattle, my pet. It takes focus and effort. I do it because I like the independence and do not have any more spam than my big three accounts. Delivery was only an issue once. Microsoft. I filed a request to fix it. They fixed it in a couple of days for free.

I don't need to run a server to run a local email client.

I also don't have the requirement for anyone to be able to join a project-specific IRC channel I'm hosting. In fact, quite the opposite, I DON'T want just anyone to join it.

For secure communication, I still use S/MIME (I may be in one of the last clusters of people to do so.)

It's entirely possible this article was not intended for you. It sounds like you have different requirements than the OP.

I tried and tried to get co-workers to use S/MIME. I was reliably able to get one other person on board, but no one else wanted the go through the hassle (and its not that much hassle!). So the two of us eventually abandoned it.

Correct, the real issue is - the most beneficial thing for users is to only share data as needed, but what scaled and was profitable was "leak everybody's data everywhere all the time."

Now, the cracks are showing in this approach, mostly because of the ones who do it poorly. Perhaps the ones to watch out for though, are the ones who do it well, e.g. Google Apps?

You don't actually need to run a server for bookmark management (his example).

I ran my own email server for a while and to be frank, it was a pain in the butt. Even though I spent a lot of time reading up on the proper way to set things up and tried to apply that as well as I was able, there was this lingering feeling that something somewhere was misconfigured, if not from a mail authentication/anti-spam standpoint, then from a network vulnerability one, and of course it needed to be continually maintained with patches, config updates, etc.

Eventually I gave up and moved to Fastmail. The few dollars per month are worth it.

Syncthing on the other hand I found pretty reasonable when I still had need for it, with my only gripe being that the only UI surfaced by several clients is a webpage which feels a bit janky.

Many people run their own NAS which is the non-cloud alternative to something like Google Drive.

Running your own email server is a pain, having a client that pulls down your emails and stores them on a NAS so that your email is only briefly stored in the cloud is not a pain.

Never used WhatsApp or Telegram so no idea what the alternative for those is.

All these solutions are too complicated for an average person. Anything requiring typing command lines of any sort is too complicated for 99% of people.

And setting up your own email requires intricate knowledge of modern anti-spam protocols and reputation management.

Because to run it 24/7 you need maintenance. And proper HW to run it in home environment. And ISP... And...