I thinks this is where our difference in comes from.

When we are reading code, we are not usually reading the strings contained within.

We are reading variables names, we are looking at where they are used, where they are assigned, stuff like that.

I very rarely look inside the strings when we are actually reading code. When reading code, strings are just black boxes where nothing can happen. So we can completely ignore them.

With this pep, that will change. And readability takes a big hit. Strings are no longer black boxes.

And actually you can get the " {value} if very long text" format right now using the format function, but it right now requires an explicit list/dictionary of variables.

This explicit list of variables really helps in the context of reading code. And forcing users to write down that explicit list of variables to use, is good.