I mean, if we're talking about sex, I'll say that I love athletic wear on athletic-looking women. I guess the scarcity of athletic-looking people might be part of the problem.
- an abundance of electric lighting
- media to distract them and personal portable screens with access to such. Personal is important since even a television screen watched by 2 people offers more of a social experience than those same 2 people each bent over their personal screens.
- contraceptives
- state pensions
- education, for good and for bad
- a relentless drive to consume, consume and consume for the sake of it
- life success measured by the number of ephemeral gadgets you collect - your great-grandfather's golden pocket watch was a status symbol for life while your Apple watch is outdated in one or two years.
To be sure, there were some things which people had back then which they do not have now for the most:
- religion - many people met their partner while going to church
- marriage was far more common
- contact with their neighbourhood - people knew their street/hamlet/village, they met them on the street, in shops, pubs, church, at work, etc.
- public social gatherings of sufficiently large size to meet that girl from the next town and of sufficiently small size to meet her at the next event.
Read some Robert Putnam. This was happening well before screens could be blamed.
If it wasn’t phones, it’d be newspapers. People will find devices to keep to themselves in public.