Am grid engineer. You nailed it. It can get incredibly complex modelling this stuff, and reading all the armchair observers banging on about 'single points of failure' is amusing.
My professor did that for Bonneville Power Administration. I worked on a tiny piece of his modelling software. A short writeup of it https://ciex-software.com/fmcmx.html
Oh yeah. These posts are the limit of my knowledge. Real-world power plants, switchgear, and grid management is way way more complex! And if you want to talk about "hard real time requirements".... it doesn't get much harder or real time than keeping the grid going :)
Thanks to you, the operators, and the linemen out there keeping it all going. When it works correctly no one notices.