The original UTF-16 can only represent 65536 code points, what is less than half the number of unicode codes today. It was broken at the expansion around a decade ago.
There's a new, incompatible ("mostly compatible" may explain it better) UTF-16 encoding that represent all unicode codes, but well two formats with the same name is even more broken than only a broken one.
UTF-32 will suffer the same fate as UTF-16 if unicode expands. And UTF-8 is capable of representing an absolutely huge number of codes, requiring only non-breaking extensions.
There's a new, incompatible ("mostly compatible" may explain it better) UTF-16 encoding that represent all unicode codes, but well two formats with the same name is even more broken than only a broken one.
UTF-32 will suffer the same fate as UTF-16 if unicode expands. And UTF-8 is capable of representing an absolutely huge number of codes, requiring only non-breaking extensions.