While it may be true that other cultures are more introvert-friendly than ours, that doesn't change the fact that, even if you can find a theoretical environment in which introvert aren't at disadvantage when it comes to dating and sex, you can't just change culture like that. I often these statements from psychologists "X would be better if our culture were different" but making a culture different is difficult to say the least. Arranged marriages - and for some any marriage at all - are now seen as intolerably misogynistic, on top of which is added the notion that love is "random" and can't and shouldn't be interfered with because nature. Such a culture is highly unfavorable to introverts but will not go away. I still feel like biological interventions would be the only attainable way out (but those are also looked down).