In the 90s I was a kid so the below is from that perspective.
What did we do in the 90s before the internet? Read! I was lucky enough to have access to a collection of world encyclopedias which I spent a LOT of time reading. Ranger Rick (magazine) was huge for me as a kid - read those things over and over. A kind neighbor lady would save her LA Times newspapers for me and I cherished and read those over and over.
And yes, I was allowed to ride my bike down the street to play baseball with the kids on the block as long as I was home before dark. Had no cellphone, nothing. If you needed to communicate you had to use a landline phone to call - borrowing people's phones was acceptable as long as it was local.
Every night at a specific time (I can't remember if it was every week or once a week) there would be programs on the TV that we'd watch - Cheers, Hunter, Star Trek TNG at night. In the morning you'd get Andy Griffith, Gilligan's Island, Beverly Hill Billies. Sesame Street, Reading Rainbow on the weekends. Weekends often had "reruns" of your favorite shows all day long (Star Trek (Kirk)). You'd keep an eye out for TV Guide in the newspaper to find out what shows you wanted to watch. Just be careful, if you didn't shut the dryer off all the way, it would affect the TV! PBS was huge for me as a kid - nature shows, etc.
In the summer, us kids would find a kind neighbor who would let us use their pool - so we'd ALL go over there and do that.
There were many hours spending alone in the backyard playing with cars, building mud forts, using your imagination because parents would only let you watch so much TV or you'd rot your brain.
Events with friends was a highlight - but you rarely got to talk with them because at least mine were all long distance calls and I only saw them a few days a week (church - which usually met Sundays/Wednesdays). When we did spend time together it was spent playing sports, going to museums, watching movies in the theaters, seeing sights, going hiking in the mountains (camping was big).
My thoughts: It was not lonely at all. You'd use your imagination at home when you were at home - doing circles in the backyard on your bike pretending to be a semi, reading books, watching VHS tapes of Disney movies, and yes, hanging out with neighborhood kids/people/friends. If anything, not having constant access to friends made the times we spent with friends far more rewarding - made people work hard to make those interactions more enjoyable. You'd really look forward to summer vacation.
When we got access to the internet it was mind blowing to be able to send email via AOL to family across the country instantly. I could also pull up websites that gave me pictures of World War II airplanes - took 5-10 mins to load those photos. Family computer was in the living room so that kept us kids out of things we shouldn't. lol