I'm disagreeing on the fact that you're based on an assumption of a big amount in a video from fanboys who are only looking at one side of the equation. A specific type of plugins that normally are only in a part of a project (mixing stage), and a song can have infinite complexity - and surely it is not the mix that will bring your machine down, specially if your base project is audio. So thought I agree that computers will get more and more "out of the way" they will still be there, and you still have to think about those stuff depending on a project.
Track count, plugin count, instance count, it all doesn't matter if you can bring your machine down with the new synth in the block. So most things evolve and plugins evolve too - thus what I said about complexity and context.
That being said, creatively, I don't think anyone is thinking about track and plugin count while creating a project. You just add what you think is right, and work your way around limitations, and knowing your tools is and will always be part of the craft. But for the aforementioned reasons, the blissful state you described is probably unattainable.
You can get that sort of "bliss" from a good instrument. A great piano, built on hundreds of years of craft that does what it does perfectly, and you achieved your best at it - you just think about the music you're making and that's it. Different worlds though!