Germination and seedling

Mate, I've popped a few seed in the last couple of years and sometimes they are growing like a rocket, germinating in three days directly in substrate, dropping their shell off and just being vigorous - and sometimes they spent 24-48h in water, then in paper towel, then in substrate, they might not pop at all or pop and die because of multiple reasons. After 10-14 days I usually pronounce them dead and start a new seed. Seeds are tender, some people even sterilize everything before touching them. Of course genetics are important, but sometimes even the top breeders' seeds can fail unfortunately.