We (IPinfo) have a practice of adopting low-maintenance, high-utility services. Generally, we adopt websites that would have become defunct and run them as services.
Even though IANA says example.com is intended for documentation purposes and not as a service, I feel that it nonetheless serves as a service to the broader internet. I think there are some cornerstone services on the internet, regardless of the maintainers' intentions or their legal definitions.
For example, we ourselves sometimes have to recognize that we are not a standard API service. Considering that we expect to process 3 trillion requests this year, a major outage could take down a good chunk of IT systems everywhere. So, we invested in infrastructure to avoid outages. We then started adopting other cornerstone services and running them indefinitely because we might as well support the users who depend on them because we have infrastructure to support them and us.
I think what you describe is exactly right, it has organically become a service and it is maintained with that in mind. That doesn't mean you shouldn't be clear about what its for and what should be avoided. Otherwise it is setting up an implicit contract that it will service those needs without limitation which turns it into an even bigger dependency.
Example.com is one of the sites I visit most often for troubleshooting my connection on the go. It's great for tickling a captive Wi-Fi login that didn't trigger properly.
For a moment I thought you were saying ipinfo runs example.com.
Instead it just seems to be an advert for ipinfo on a post about example.com?