Just to make sure there's no misunderstanding, keyword research
is still extremely
What is useless is the keyword meta tag
You still need keyword research to learn what words and phrases real customers are using when they search for the kinds of products or services you offer.
And you still need to pick different phrases to use for optimizing each page of your site. Attempting on-page optimization without first doing keyword research is... well... not optimal.
And you still need to optimize different pages of your site for each of these phrases. That's what makes it possible for the search engines to rank your pages highly for those phrases... which is what makes it possible for potential visitors to find
your pages when they search using those phrases.
It's only the silly lists of keywords in the keyword meta tag that are "dead" as far as Google is concerned... and have been so for a long time, actually. Many professional SEOs (the ones who know what they're talking about, that is) have been saying the keyword meta tag is useless for years
now. (It's always been easy enough to test it and see that it had no effect.) It's just that Google is only now getting around to "officially" confirming it.