You want a real answer?
There's been a huge gap in the entertainment market for content aimed at modern women. I am talking quantity, quality, diversity and everything else under the umbrella.
This stems from how back in the day, women weren't able to make their own money as they were denied education and independence. Therefore the majority of marketing was aimed towards men because men were the ones who had disposable income. Of course some things were marketed to women too, but mostly either whatever was bare miniumum to keep them satisficed with the status quo, or things that would improve a woman's standings with her man (perfumes, fashions, etc).
Now, the world has changed quite a bit since then, and over the last 10-ish years there's been a sharp demand in things that appeal to women. More and more women are experiencing independence and have disposable income, but do not have nearly the same quantity of things to choose from like men have.
This is reflected in vtubing as well. The majority of idol-fans and vtuber fans were primarily male because that's what the industry marketed itself for. However, there was an interest coming from women that was being left unmet, so when Luxiem debuted there was very clear, solid evidence that women were also part of the market.
Essentially, imagine growing an oasis in the middle of a desert. You are going to see activity pretty quickly. Male vtubers went right because they decided to explore a previously unmet market, and now that market is stabilizing because there's more content to pick from. So yeah, Luxiem will not be the kings forever as more and more male vtubers debut, but this isn't necessarily a negative for male vtubing as a whole.
tl;dr: pander to women and they will repay you.
