> I would expect more would join to gain that advantage. Likewise, men having such unfavorable odds, I would expect they would drop out

The issue is inelastic demand, especially in the serious dating/non-hookup category.

Most people are looking for 1 mate; there's little desire to continue past finding one, and little desire to quit when not finding one.

So point-in-time membership of dating sites tends to amplify existing skews.

> Do the apps repel (attractive) women?

The stereotype is that men are attracted to beauty and women to power. The former is inherently more readily represented on a dating app.