There are not more than 65,000 Chinese characters in common use today. Indeed, a college graduate from this region would probably only recognize 1/10th that num

There are not more than 65,000 Chinese characters in common use today. Indeed, a college graduate from this region would probably only recognize 1/10th that number, even from Taiwan or Hong Kong (where a greater number of traditional characters are used). If the goal is simply to encode one point for each character in use today, 16 bits is very likely sufficient. That's not what Unicode does though. Unicode encodes many duplicate characters (because they are duplicated in a national encoding standard and the round-trip compatibility requirement). Unicode also includes every possible variant that is of cultural or academic interest, including dead languages and so-called "ghost characters" that are actually printing errors in old paper dictionaries or census data, but now allocated a code point. And this is before we say anything about emoji... So from today's perspective 16 bit encoding space is laughably small. But it is true that basically any message meant to be consumed by the general population, including CJKV languages but notably not emoji, can be fully represented with characters found on the BMP, which can be faithfully encoded in UCS-2.