I do think that it is easier to make a 6# rifle that will shoot .5 MOA than to ensure that your light rifle shooting technique does not add .25 MOA to your results. The former only requires the application of money; the latter demands time, attentiveness, and diligent effort. As an illustration, I have a 40X-based bench gun in .22lr that is truly a one hole gun. I also have a NULA .22lr that weighs about half as much, and I really think that its inherent accuracy is virtually as good. But it only takes the slightest slip up in my attention to technique to start to throw shots out with the NULA.
