I think committed relationships are on the decline more because of the change in how women interact with and are viewed by society, than technology. Each successive generation of women over the last several decades has increased their ability to earn an independent successful living, control their sex life without negative labels, and remove the expectations that their only value is domestic-oriented.

Where in the past women settled for a number of reasons, including economic and societal/familial expectations, they no longer do. And because women are much less apt to settle down, men settle down less too. More free women = more free men = less committed relationships. (assuming we are seeing fewer committed relationships - I didn't fact-check that)

Not at all scientific, just a vibe.