Well, it's easy to use for users, it maintains itself for the most part and doesn't break compatibility. It is also easy to setup. And to customize. It provides

Well, it's easy to use for users, it maintains itself for the most part and doesn't break compatibility. It is also easy to setup. And to customize. It provides many tools out of the box, including though you would not think. An example that surprised me is the automatic addition of lazy loading for images at some point when browsers started supporting it natively without any intervention from me, which is very good. With a caching plugin it's as fast as a static website most of the time, which gets me 100% on Page Speed Insight, and the hosting is on a domestic connection. I've made sure to not use too many extensions and javascript-heavy things, to disable some stuff and avoid huge assets but I've not spent that much effort on it. I've been maintaining a few WordPress websites since 2015 and I would chose WordPress again today for any new site on which non technical people must intervene (to write or manage content). It just works and is user friendly. I'm not sure any CMS would save you if you don't do your security homework though.