There's a difference between preparing your team for a powerful threat, and using whats arguably a niche mon or set just to beat a certain Pokemon that completely shreds stall and balance.
Just because its not popular or "old" does not mean it isn't any less suspect worthy or broken. That has no relevance whatsoever.
Please list these reasons as I and a few other people had great stall teams that became useless once SubBU Braviary was discovered. I would like to know this "laundry list of reasons".
So Jynx wasn't broken because it could be used on balance? This logic doesn't make any sense whatsoever. I could use SubBu Braviary on stall but that doesn't have an bearing on whether or not its broken. And it does in fact shred a lot of balance teams. Balance teams generally have 2-3 defensive pokemon like the Regen core which is set up all over by Braviary.
This is where your post starts bothering me because it seems like you've never actually used Braviary before. What fast Taunt/Encore users are you talking about? The only ones I can think of that are even viable are Kadabra and Skuntank. Notice how I said viable because shit like Emolga and Persian should NOT be brought up in this discussion.
The only common electrics that use Static are Ampharos, Electabuzz, and (I say this because its used) Pikachu. Rotom-S, Eelektross, Rotom-F do not have Static. And really Electabuzz and Pikachu aren't that common so I probably shouldn't have said them but I know somebody would've brought them up.
I won't even respond to this because its simply not true and just stated with no facts to back it up. There are plenty of times where myself and people I've watched, have swept entire teams with Sub BU Braviary and there was nothing the opponent could do.
It does set up on Rock Types. Here's what your missing: Rock Blast doesn't hit five times in a row every time. So Braviary takes however much from Rock Blast and keeps Roosting until its at a decent health and then Bulks Up again. So now your Rock Blast is doing less and less as the process repeats. This is how Braviary beats nearly every rock type we have at our disposal.