As someone that happens to using e/os on a phone with an unofficial device. You are technically correct. They offer custom Roms for a variety of devices that you can install however they also have their own range of devices which admittedly is lack luster in terms of price to performance. From what I gather those devices try to follow in the footsteps of the Fairphone but with all the growing pains of a startup... I like the os. they offer cloud services as an addon that you can pay for which is based on nextcloud. The integration with the cloud services in surprisingly deep. Coming back to the fact that its based on nextcloud you also have the option to self host (which I recommend) and still benefit from the tight integration and that aspect alone is a major reason why I'm still using it. Gallery, notes,backups,cloud storage. All the Google like service's built in but without the Google
Worth mentioning to those unfamiliar with e/os is it comes with a built in app store "app lounge" that also has access to play store apps so you don't even need to go to the effort of installing aurora. One less thing you have to do