Earlier quoted context omitted.
More money. Smaller companies can't compete with FAANG salaries. So when FAANG prioritizes hiring women, and there are still many fewer women than men in tech overall, smaller and poorer companies can't compete with the offers women are getting from FAANG.
... sure, on the other hand way less competition, and smaller companies can also simply go ahead hire promising juniors and do on the job training.
Not before FAANG hired the promising juniors first, FAANG are very willing to give on the job training. Or at least were a couple of years ago.