As far as pure writing goes, there was nothing Bank Street Writer on my old Apple II+ lacked, aside from spell checking. (I think. It's been so long, I'm not 100% sure, but spell checking would have been a major chunk of resources in those days.) When it comes to formatting and presentation, there has been tremendous progress. Most of the functionality word processors really need has been around for since the 80's in the mainstream and the 70's in research labs.
(P.S. I don't think spell checking came around until BSW version 3.)
Well the ][+ did lack lower case characters and only 40 columns of text...... The Apple //e fixed that with a huge 80 columns and lower case!
Spell checking was usually a separate program on a separate disk run as a last step. I used to use apple writer and apple works and used websters spell check.
(P.S. I don't think spell checking came around until BSW version 3.)