Not in the category of "unnecessary sequels"

Rating: 9/10 (25 August 2015)

The action of this film is not less than satisfying, unless you came for Matt Damon. Although Jason Bourne's fighting would be more worth the watch; Renner's character is a fine addition to the Bourne franchise-plot, as he is the subject of a new conflict that sensibly is a result of the same CIA-conflicts that arose from the three movies before.
With that in mind, with there being no plot-holes nor bad acting (when one watches a second or third time), and with good ways that they tie in literal events of Bourne Ultimatum consistently with the goings- on in this one, it is wrong to say that The Bourne Legacy has caused the much-beloved series to "decline".
Bourne Ultimatum is indeed the high point of the series, but regardless, this film is a perfect example and option for a "agent vs agency complications" movie.