Formalizing f-strings

I'm probably as used to straight ASCII quotation marks (and irritated by other styles) as any, but I feel this is could be a case where we don't understand what we're missing out on. Would you also say we wouldn't need separate left and right parentheses if we could just triple them, like |||?

When I think about it, it just seems kind of nonsensical to use the same thing to start and end something.