That's what zsh did; $var is always the value of $var. Want field splitting? Use $=var. Want globbing? Use $~var.
I think bash is stuck in 1988 and is a poor clone of ksh. I think it's highly unfortunate it became the "de-facto 'modern' standard".
Perhaps you're right. Perhaps. However, the most important consequence of bash creation and dissemination is that there is a de-facto standard.
So until we don't have another de-facto standard hundreds of thousands of typical shell users are happy with bash. With all its issues, weaknesses and disadvantages...
I also think the value of being the de-facto standard is somewhat overrated (as is the value of portability by the way); many scripts only run on one platform, one you control. zsh is not hard to install.