It seems to me that just because buzzwords start appearing on job descriptions doesn't mean that they are what determines who gets the job when push comes to shove.

The job description is the idealized vision on the candidate. You can't really read into it whether the hiring team will choose social skills over competence, or even whether they'll get a good read on either in the interview process. On the description they want both.

As for competence trumping cultural fit, there is a tradeoff there. It may depend on the specific role being sought (the bar for competence), but taking a poor cultural fit has more consequences than messing up your agile methodology. It can hurt retention of other competent employees, among other things.