There's no real purpose for BA on DBs, unless you had a really niche build that did a lot of blitzing--since the roll only comes into play for those set to blitzing the QB in the play call. For the d-line, BA is definitely underrated, because it often allows the DE to nab the RB before he has time to pick up speed and accelerate to the outside--making the tackle roll easier to win AND making TFLs more likely, provided you break off the block. Similar story for DTs reacting to and getting in position against inside runs.
Blitz awareness speeds up the process of a blitzer shifting away from attempting to pass-rush after the QB and toward going after the RB. Especially when combined with Pursuit and Balance, I've found it pretty valuable in getting my DEs into the backfield to stop outside runs before the RBs get fully into the outside hash.
For what it's worth, my non-superstar DEs with 50-53 sprinting, relatively low Break Run Block, ~50 BA/Pursuit
routinely get significantly more tackles and TFLs than even most superstar DEs. BA speeds up the process of breaking off blocks, and Pursuit helps them weave through blockers to get to the back.
They're far from perfect builds, but the unique sort of stat lines of these builds might give you an idea how BA/Pursuit affect their run-stopping ability.
https://glb2.warriorgeneral.com/game/player/282488https://glb2.warriorgeneral.com/game/player/282333