If you listen to everyone, you'll get one opinion per person...some say they can make forms work, some say it's useless, same with drills, sparring etc...
So where's the truth? Probably in the middle...
Here's how I see martial arts...it's like religion: you got to believe, you got to do it and believe hard. Like in religion, maybe you'll never get the chance to see if your belief was right, or maybe when you see it it's too late...
The only thing that can tell you if your practice is useful in fights are...fights...but the problem is that if it doesn't work out, does it mean your practice is no good? Who lost, you or the practice? It would be too stupid to drop a valid stuff (whatever it is) just because you lost a fight...but is it valid if you lost? In a fight you have no time to analyze why things work or not, you just see if it did work or not...and by the time you start to analyze it in the comfort of your kwoon, it's gone, you're not in a fighting situation, you might lose the essence.
If you win, you'll be convinced that it is useful...but what if you won by chance? or by a natural talent? or by a failure from your opponent? You cannot be sure about that either...
So when you see things both ways, there's no way to know what really works, and what doesn't...
So all you got to do is practice, and believe, believe, believe...