You are mistaking the problems with WordPress as something that is inherit in PHP. That might have been true years ago, but modern php (php7 and hhvm) is a very powerful and mature language with rock solid performance, and in the case of hhvm that performance is equal to native,and in many cases faster than even C++. When written correctly and running in the right architecture it scales seemlessly and delivers low latency and high throughput. Sorry if you thought you could pay some indian 3 bucks an hour to slap together a wordpress site and be the next facebook.
Finally, I would like also to draw attention to another interesting CMS that I used a decade ago and really enjoyed using at the time: it was originally known as Article Manager, and its current incarnation is CMS Builder, from InteractiveTools (a company based in Vancouver). At the time I was using it, I remember that the developers were very helpful, and the forum was lively and helpful too. Now that I am using WP, I would not really consider moving to CMS Builder (although I own a license), since WP offers much more in my view. But some people might have reasons to prefer it. However, one should pay attention to the fact that some of the add-ons can make it more expensive than the initial $200 price for a single site.
Amongst most of the website builders, another name that comes to mind is Squarespace. The versatile builder for blogs, portfolio sites as well as online stores, has managed to rise in its popularity in the recent years. Despite the huge difference, this being a closed source software while WordPress is an open source; it certainly is a great alternative to WordPress Page builder. That’s right, for the casual users the overall functionality and the flexibility is the main aspect.