I had no Princess of Power figures a kid, but my sister did. We had the whole universe. I can speak on behalf of how it affected my sister. She-Ra finally gave girls an action figure line. My sister was always into fantasy, and I do recall POP gave a reason for girls to not be so girly, while still being girly (doll enough, mothers didn't mind buying for their daughters). A lot of the She-Ra characters were positive role models of strong women that weren't the typical boring stereotypical female. My sister loathed Barbie, because she wasn't the kind of kid that idolized stereotypical female chattiness, shopping, and fashion. She-Ra allowed my sister to be herself while still having something unique to her gender. She-Ra gave tomboys a chance to be comfortable in their own skin.
The fantasy from Princess of Power appealed to my sister's artistic talent. She later became a graphic artist in her career (and is the one who made some cool She-Ra Sims a number of years ago). At one point, I recall googling "She-Ra", and one of her Sims came up as the third image on the search!