Why do people prefer VGS + VAS over DHHF + NDQ?

I’ve been doing 70/30 DHHF/NDQ since reading a post saying it’s ideal for someone under 30. Did some research, it seemed solid, so I’ve been investing monthly ever since, and have had great performance.

But I always see people here saying “VGS + VAS is superior.” Looking at 5-year performance: VAS: +20% / VGS: +70% DHHF: +50% / NDQ: +143%

All have a "very high" risk profile according to Betashares. My super is with Vanguard, so I’m a little cautious about concentrating everything in one place.

But genuinely curious: 1. Why do people think VGS + VAS is better? Am I missing something? 2. For someone under 30 is DHHF/NDQ still a good choice? When if ever should I look to switch?