Why is maturity such a rare thing for this and younger generations?

Like It’s so embarrassing how so many people are immature nowadays. People have no sense of maturity and responsibility. People think they act however they want and if you’re being serious to them they either call you old or a killjoy. etc. I’m a Gen z too but I’m still embarrassed by the type of people nowadays in the same generation. Like is maturity that bad?
Why is maturity such a rare thing for this and younger generations?
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