Currently Drupal 7.x core updates involve multiple steps and a decent amount of Drupal knowledge.
Currently Drupal 8.x updates can be done with a single command, so long as the website builder has installed the SSH CLI composer utility, a unix command line utility. Once the setup is done it can most of the time be relatively painless. But for many potential Drupal website builders, they do not have command line access to their website server. This problem also means that hosting companies need to be educated about Drupal 8 requirements.
However, to make future Drupal updates “easy for forever”, Drupal needs and order of magnitude better internal dependency and updating infrastructure. If other CMS tools have solved this problem, Drupal’s developers should be able to as well, to provide admin UI one click Drupal core updates. Drupal website maintainers will still need to make backups and so forth, but the update itself should be done with all the infrastructure of the “composer” utility built right into Drupal’s admin system itself and integrated with the Drupal admin GUI.
This ought to be a priority for the future development focus of Drupal core, along with an order of magnitude better support for media (images, audio, video) integration into Drupal website building and maintenance.