i don't think certain submissions are ineffective, just the old set ups for them. in mma enough people work thier bjj game so they can at the very least avoid subs. for example: armbar from mount. no one is going to stick thier arms up because they know what can happen. modern fighters can't just sit back and wait for people to make mistakes, they have to force them. by using a slightly different set up and applying more pressure to the opponent you can still get the armbar from mount, just not the old fashioned way. thats what makes the sport so dynamic, people learn how to avoid things, other people learn new ways to use things, people learn to avoid those things etc... the sport continues to grow and be viable....