On a quest for the perfect CMS

Now all of these things are not real problems. Composer is easy enough to implement, using wpackagist and this fork of WP on GitHub. The awesome Timber plugin brings twig to your themes, as well as a better separation of front end view and logic. Don't install badly written plugins, cache things properly and away you go. However, it'd be nicer to have all of this natively.

I've tried many other alternatives and never found something that comes close to WP+ACF in terms of flexibility and ease of use.

Bolt was very promising but then it started becoming temperamental on my setup. Also, not the same flexibility.

GravCMS is great (and runs this site!). However, it's very much developer oriented. Couldn't really use that for a client's project. And also, not the same flexibility.

Craft looks as good in terms of flexibility, however, not free, no composer, based on Yii... I'm yet to try though.

And amongst others, I could also name OctoberCMS, the obvious Drupal and Joomla, SilverStripe etc...

In conclusion, WordPress is going to remain the CMS I default to for the forseeable future, unless the project has specific requirements. When you know how to deal with it, it's not so bad really. After all, if it powers 27% of the web, it must be for a good reason! I will keep an eye open though, we never know what might come up...