To save a Google for anyone like me - there’s nothing wrong with utf8. The problem was that MySQL had a broken implementation of utf8 (“utf8mb3”) which only supported Unicode characters which fit in 3 bytes. As a result you couldn’t save any data in your database which contained emoji.

This is upsetting because until recently if you asked for a utf8 column, this is what you got instead. You got something which was almost, but not quite compatible with utf8.