

“Because it would require changes” doesn’t answer OPs question. They want to know why wasn’t it done like this in the first place, and why aren’t we making the changes to make it happen now. Of course changing things would require changes.
It’s like answering a “why are stop lights red?” question with “It wouldn’t work because stop lights factories uses red bulbs and laws require them to be red”.
And that’s a much better answer!