Cotyledons for dicots like cannabis contain nutrients from the endosperm for a seedling.
That's starvation rations for the seedling that can absorb and use nutes from the roots right from the start like it would naturally.
I usually sprout my seeds in small 9-hole seedling pots filled with ProMix that I've soaked good with seaweed ferts or a low dose of 3-part. They can go a week or longer before needing any more water and would not do as well with no food. I keep them in a humidity dome until true leaves are well formed. If destined for DWC then it's the 3-part nutes. Organic stuff in DWC seems to lead to root rot issues.
With 18 hours of good light per day they can do a lot better than they could waking up in the cold ground of spring in the wild and need food for the energy to do well.
Sprout a seed in fertile media and one in rockwool then give both nothing but water for two weeks and see which does better.
Two weeks with nothing but water for a struggling seedling of any plant variety doesn't make sense. Fine if it's in real dirt like I've said before and mostly that refers to people who've planted in good soil and asking when to start feeding nutes on top of what's in the soil.
I'm liking these 3" flimsy little nursery pots better nowadays. 18 fit into the standard seedling tray and the sprouts seem to do way better when started in the larger pot and can get a good size then go straight into a 4gal until the end. I bought 8 flats of 18 a couple years ago so all stocked up.