My uneducated guess is that Endless OS pays manufacturers to have their OS installed as it has what appears to be privacy-conscious telemetry. It won't be anywhere close to what Microsoft/Apple, but in the Linux telemetry world of the blind, the one-eyed man is king, and so it'll still have valuable data.

Some of the areas that are unlike most other distros I've come across:

• Their website for Endless OS does a lot of tracking and has a policy that is more 'business-orientated' than many distros
• Privacy policy for the OS is not available online, only when downloading program
• They use dark patterns to have the default for telemetry as 'opt-in' which might be the opposite for FOSS IIRC
• Complete list of things tracked here

To me, it's akin to the free third party apps that come packaged with many Android mobile devices. Less intrusive since it's anonymized, but also feels more intrusive because it's the entire OS being monitored. I believe I came across a headline that Fedora is attempting to use the same tracking software in the link above

This review shares a more judgmental view of their practices

This article has a more positive spin