Maybe my history is rusty. Some of the weird bold (and even font like Gothic) came from mathematics because mathematicians use them in a semantically significant way (like Gothic G is a different signifier than just G; you can’t “plaintext” the former to G and still have it mean the same thing).[1] The general preference of Unicode is to relegate style-looking things to markup. That’s certainly their stance on superscript digits (the ones in Unicode are just for compatibility). But for some reason (again rusty history) these format-looking characters had to be included as separate code points.

The point is that Unicode has to deal with how text has been used by various communities in order to be the text encoding standard to rule them all.

[1] Unlike in prose where bold and such is just for emphasis. And at worst you can use informal markup (similar to MarkDown) and convey the same thing.