I had no money, because you can't pay almost $100K in student loans and $900/mo in rent when you make $37K/year before taxes. I never went anywhere when my friends did.
I was the only person in my friend group that liked certain hobbies and social media wasn't that big back then (my main social media sites up until that point were blackplanet and geosites- Facebook had JUST come out) so there was no way for me to connect with like-minded individuals about things I really cared about.
I went to school ~600 miles away from my family in a city of ~35k people and only 88 of them were the same ethnicity as I, so I had to suppress most of my personality to "not stand out", which strained my relationship with my partner and led to a surprise breakup.
By the time I hit 22 I was legit prepared to end it all- I even left a "final farewell" note on /b just to give them one last "rofl" on the way out.
A full decade later I look back and realize that it wasn't my shitty job or financial situation. It wasn't being in a minority group in a hostile school or the breakup. I wasn't (committed to being) suicidal. I was literally just being an edgy dingleberry. My problem was 100% made up and I was just looking for ANY reason to stay trapped in a cycle of sadness. Eventually it just... Went away? At some point at 24 something changed in my brain where all of a sudden I want thinking about how lonely I was.
None of it had anything to really do with social interaction, at least not ACTUAL interaction. It felt like I was just bitter because I couldn't do all the stuff I WANTED to do, and that stuff just happened to be related to social interaction. Maybe my scenario isn't the same as what you're describing but I don't think smartphones/social media were my issue. I just needed to mature a bit more and not be so focused on what I COULDN'T do.
Having said that while I think smartphones are one of the most influential inventions to come out since the turn of the millennium... The biggest social media sites are a net drain on society and I would not be sad to see them go in the slightest.