Think BR's will be used far more often now that there is an auto attack, hopefully auto attack continues while in BR mode.

BR is very effective right now as long as you don't take forever to do them. Most leve monsters don't need them though because of their low health, but SP parties and NM parties get good use out of them.

Skill chains were nice, but they were not very accomodating outside the few people that were apart of them and were entirely ignored once you got to endgame because WS spam was far better. I think people forget just how useless Skill chains were, maybe nostalgic for their SP parties, but in the end they were pretty bad. BRs allow everyone to get in on the action and they are actually extremely effective. So, I'd honestly consider BR > SC funadmentally better, but like all things FFXIV it will need some work to make it great.