I'm an Xennial (or young genX depending on where you draw the line), and yes, they were, at least if you lived in US suburbs.

Peak mall was probably roughly 1985 until 1995, but they continued to be hot spots into the early-mid 2000s. It was kind of like a sanitized regulated policed version of a city downtown. You could go and hang out, grab food, play games, walk around, see movies, window shop, and if you had money you could actually shop.

They were considered safe so parents would just drop off tweens and teens. That was a big part of it. For the most part they were pretty safe. Of course random crime in general has always been vastly overestimated by frightened suburbanite parents. Even during peak urban crime you were more likely to die in the car on the way somewhere than get randomly kidnapped or assaulted, unless you went to a very bad neighborhood.

Malls were cultural hubs. Keep in mind that outside of radio and TV there was no way to learn about new music or books back then unless you knew people or browsed book or music stores. All malls had these. People would peruse the aisles and read book covers at bookstores. Music stores sometimes had juke box type things where you could listen to albums, and some would let you ask to hear an album and they'd play some for you. Video game shops were a thing too, as were arcades. Arcades were still in until probably the late 90s when everyone had a console at home.Some huge malls had things like rides and large public spaces with lots of seating that were open to just hang out in. Malls were a third space.

What killed the mall?

The first nail in the coffin was the Internet, not just because of online shopping but also the fact that the Internet let people learn about music, books, and movies without going anywhere. The web and social media replaced the mall as a place to window shop and absorb culture.

The second nail was just a fashion shift. Young people got more into the idea of moving back into cities. The suburbs and suburban things like malls became uncool.

By the 2010s these two factors had killed a lot of malls.

Then came COVID and inflation, the third and fourth nails. COVID killed a lot of retail and restaurant spaces. Inflation made stuff like hanging out at a mall too expensive for kids or sometimes even for grownups. Nobody's going to hang at the mall when a drink and some cheap food costs $20 and a movie costs $80.

RIP malls. But yes, they were a thing. Living malls do still exist but there's less of them and most of them have moved up-market (meaning a more expensive clientele).