Though this is an old topic, it's still very relevant. I like to play around with things, had extra time due to Covid-19, so decided to build a road wheelset without interlaced spokes. 2X rear both sides. I've got maybe 500 miles on it and I don't detect any differences between it and similar interlaced wheelsets I've built. Spokes are still tight and wheels are still true. Whether that would hold at 2,500 or 5,000 miles is anyone's guess. I think some of it has to do with the components you use. I used stout components and nipple washers. Maybe specifically-engineered components are why some high-end wheel manufacturers don't interlace the spokes on their wheels? Or may they don't interlace them because they don't want the wheels to last forever.
But, in any case, I've decided that I will never again build a non-interlaced wheel. There's no reason to tempt fate. Wear a helmet, check your brakes, keep your chain clean and interlace your spokes.