I am not too sure what is the intended end point of these speculative discussions but aren't you tackling the problem in reverse?
The Amiga was special because its features made it special.
The harmonious mix of hardware and software innovation was the key to both its ease of use and power.
It does not matter that it had a 68k, a blitter, and stuff. What mattered for users is what these kittens enabled. What mattered is that users got their jobs done, be it gaming, or else.
If you want to make an Amiga like modern computer, start with the features you want in, start with the job you want it to accomplish with the computer, not the components. And that's determined by software these days, not hardware.
Also I should mention that people are moving away from home computers and using more and more their mobile devices for computing tasks. Failing to address that is guaranteed death if the goal is a mainstream computer (if the goal is a niche market, then it's fine).