It’s probably because you’re calling people of 60+ ‘very old’, I’d tell you to piss off too! That might feel along way to you now, but age has a funny way of creeping up on you (I’m not ‘that’ old, but closer than you , going by your comments).

But to answer your question more seriously, one reason is likely that we’ve gone from a society that was generally positive & helped each other (in a local sense), to constant negative news via the mass media & social media, & I think it just grinds a lot of people down, especially those that remember the ‘before’ times. But if you focus on the good things in life, often again at a more local level, life can generally be good(ish) for most people (unless you’re being savagely attacked by an oppressive force, as seems to sadly be getting more common around the world 🙁).