The internet has helped make them easier, yet lower in quality at the same time.

easier tbh. how hard is it to shoot someone a message if you feel like catching up with them? and you can respond at your convenience. if we didn't have social media and just had phones, how many people would I call up just for the heck of it? not that many

That all depends on how insecure you are. People who setup fake accounts to "catch" their cheating partners in the act will never be satisfied.

harder there's no down time.. They're always around HAUNTING YOU! :)

Easier

I belong to the 'it's how you use it' school of thought - if I'm sliding into DMs behind my girl's back it's harder, if I can sext her while she's on a business trip, then it helps

Easier, obviously

Depends on degrees of the relationship

I actually neither needed or used SM for keeping in touch with friends. We text or phone each other or write e-mails.