> All Unicode codepoints obviously cannot be held in 8-bits.
I mentioned UTF-8 specifically, because the UTF-8 encoding actually does specify this particular feature:
> UTF-8 is capable of encoding all 1,112,064 valid character code points in Unicode using one to four one-byte (8-bit) code units. Code points with lower numerical values, which tend to occur more frequently, are encoded using fewer bytes. [0]
I mentioned UTF-8 specifically, because the UTF-8 encoding actually does specify this particular feature:
> UTF-8 is capable of encoding all 1,112,064 valid character code points in Unicode using one to four one-byte (8-bit) code units. Code points with lower numerical values, which tend to occur more frequently, are encoded using fewer bytes. [0]
[0] https://en.wikipedia.org/wiki/UTF-8