Comment by Xophmeister

I don’t know what you mean by “all the UTF-8 codepoints can be held inside an 8bit char”. All Unicode codepoints obviously cannot be held in 8-bits. The UTF-8 encoding matches ASCII over the first 7-bits, but that’s not relevant. You can UTF-8 encode Unicode codepoints into a bunch of 8-bit chars, but then you can encode anything you like into a bunch of 8-bit chars; a JPEG file for instance.