An Arduino is very approachable in that you can just plug it into a USB port and tell it to blink a light following a very simple tutorial. No breadboards even, just plug in a device and open a program. Under the hood the Arduino is very complex but for the end user it's very simple.
A lot of Arduino compatible modules are also simple for the end user despite being very complex under the hood.
The simplicity for the end user is I think the biggest attraction for the Arduino. In your K8s analogy, it is not simple for the end user. Someone may build some K8s monstrosity because that's what a tutorial or bootcamp taught but it's very obviously complex. The hosted JavaScript app is a better Arduino analogy, it's a complex solution under the hood but presents a relatively simple user experience.
I agree with both you and the GP. Arduinos tend to make goofing around with electronics more accessible to more people. At the same time a lot of projects could be built very simply with just a couple timer chips. It's unfortunate people reach for a relatively complex solution (Arduino etc) to what's ultimately a simple problem. They would benefit a great deal from just knowing a blinking light can be made very simply with a simple circuit.