collapse of the old society

Why?

Survival of the human species.

Which should be an extention of your own personal will to survive if you are not a sociopath, narciccist, or suicidally depressed.

The entire history of human civilization has pretty much only moved forward when we worked together with like minded goals.

This is because the power and skill one person can obtain will always be dwarfed by the power and skill obtainable by hundreds or thousands. Even the most impossible problems to solve, like landing on the Moon without computers, has been conquered through the collective will and skill of our species. But rarely, if ever, by an individual.

During the industrial age, the goal of working together was the improvement of our livelihoods and well being. Now in the information age, it's about survival.

No Billionaire has the skill or power to stop climate change.

But enough of us together do. Unquestionably.

Unless you only care about yourself and can't see the benefits of what working towards a goal that isn't your own can bring.

No offense, but your argument is that of a rich white liberal that's too insulated by money to bother reading about the overwhelming economic benefits of things like taxes, and regulations.

Basically, in case you didn't know - as someone else mentioned - you live in the same world as everyone else.

And what that means is that this world very much has an effect on your day to day life in what opportunities and options it provides you. All of which are not at all decided by you.

The quality of institutions, education, healthcare, and security you have access to are directly related to the skills and efforts of the hundreds of people running them. Not yours.

You will be better educated, have a better job, and have better health in these communities because these are things ONLY others can provide YOU.

So working towards improving these jobs, and the people doing them, also allows you access to that improvement. When a communities environment improves for all in it, that certainly includes you.

That's the short of it - but unfortunately we live in a world where billionaires have decided that's just all bullshit instead of accepted science with hundreds of years of validated experiments in sociology, economics, and anthropology to confirm.

So now because of the actions of billionaires who have been taking from all our communities for the benefit of themselves - we are now ALL in the same prisoners dillema. They have created an environment for us all where we only have the following choices:

A) Be too distracted by the firehouse of social media bullshit to do anything. B) Be a coward and convince yourself to do nothing. C) Work together to combine resources and prevent our own extinction.

Billionaires are actively working towards our own existential demise, so you are either choosing to fight against that or do nothing to let them kill us all.

So to answer WHY:

It's so the future is one where your kids are happy instead of living as slaves in a dying world. Your inaction guarantees the later result.

Bonus: everyone becomes happier when working towards a better future if you ever decide to try.