Why are seed plants the most common in nature?

The widespread distribution of seed plants is associated with the emergence of a new organ that has never before been found in the plant world. This is the seed. With the advent of the seed (gymnosperms and angiosperms), the plants succeeded in:
1) get rid of the method of fertilization using a liquid medium;
2) storage substances (endosperm) appeared in the seed, which supports the germ during development;
3) in angiosperms, together with the seed, a fruit is formed, a special formation that contributes to the spread of the plant (through animals, insects, humans).