I think a lot of the difference come from a conflation of concepts. For example, you initially talk about simplicity, but halfway through your post you start us

I think a lot of the difference come from a conflation of concepts. For example, you initially talk about simplicity, but halfway through your post you start using the word "easier". In my view simple and easy are points on two different axes. In the best of worlds you get both, but as an example, a smartphone is a very complex system that is relatively easy to operate, and a unicycle is a very simple system that's relatively hard to operate. The boundaries only break down when you need to peek and poke beyond the abstractions that make the complexity manageable. If your phone breaks down and you have to troubleshoot and fix it yourself you'd probably much rather be dealing with a unicycle from a practical point of view: there are only a handful of things that'll ever break, and you'll determine which thing broke at a glance. The potential for surprise in easy-complex systems is a good thing to keep in mind when operating a website I think.