I'd never say it was necessarily better but there is probably something, in re seriousness, in the way that more people used to read books and dress more formally and etc. Or I guess more to the point that it was much more difficult/impossible, and much less socially acceptable, to live a kind of perpetual late adolescence. People just had to grow up for the most part, whereas now, it's often a choice. Not that "grown-up" necessarily == "serious", but they are surely related.
But yes, however you slice it, seriousness us thrust upon some people by circumstances. Otherwise it's a choice you have to proactively make, or not.