It's specifically an NRL problem. Smaller players can be game changers at every other level but the way the NRL is played/officiated disadvantages smaller players who tackle low. IMO it needs to be fixed. Maybe reduced interchange part of the solution, but probably not the only thing that needs changing.
Plenty of 'smaller' players doing well in the NRL currently - I don't see it as that much of an issue really, it's a professional contact sport, only the most athletic are going to make it. Across many sports this means getting bigger, stronger and faster.
If you reduce interchange maybe some of the awesome big fellas we have running around now that weren't always the fittest may have given up and gone to another sport years ago? Maybe Fifita wouldn't have got an opportunity as early and gone over to union?
I do agree however that there is no benefit to executing a good legs tackle anymore and that is disappointing and legitimately unfair on smaller players or those with (what used to be considered) good technique.
If you rip someone down by the legs one on one all they have to do is flop their upper body around a bit and it's a penalty for not letting go when a) you tackled them like half a second ago and b) throwing your upper body around with both arms wrapped around the ball is not actually a way that you can get up so it doesn't even deserve to be considered as an attempt to play the ball.
You either let go instantly and they quickly play the ball with your defense massively on the ropes or you hang on and get penalised, if not marched off. But if you grab someone around the upper body and push them around for a bit you chew up heaps of time and then chuck them on the ground and waste plenty more time. This slows the game down a lot but is
much more effective in today's game than a good legs tackle, and a smaller guy can get even more easily dominated.
I'd rather see them have a crack at fixing this up before reducing interchange again.