Yes and no. With PHP the complexity is all still there -- you've just delegated to a shared host.
I worked on Cloud Foundry buildpacks for a while. The PHP buildpack is actually one of the more complicated ones, because at staging time it tries to recreate a shared hosting environment in a standalone container.
The Ruby buildpack is complicated for legacy reasons, but for 99% of modern apps all it really does is run bundler and rackup.
Meanwhile every PHP app wants to keep on living in the 90s.
Arguably the Java buildpack has the simplest job, if you use a sane build tool. "Here, launch this jar".
Heroku is pretty straightforward for most stuff. Python, for example, is basically "make a requirements.txt, a Procfile to tell it what the entry point file is, and then push to the Heroku repo".
It should be, but well... this is something if you're using PHP.
If you're using anything hipster (ruby, iirc python, Java) you're out of luck with that.