Even without capitalism, you have a duty to create value for the people around you, and you might expect the same of them. There are exceptions for the young, old, and infirm.
Put another way, I'll worry about a million people not "adding value" when there ceases to exist individuals who have captured enough wealth to support a million people. The latter is the real problem.
I have no such thing. I am debt free and live the way I want. I live alone. I have no children or spouse to support. I owe nothing to anybody. I don't owe anyone an explanation. Maybe the opposing views come from people who believe they do, but in no way is it universal.
Your point from the perspective of wealth inequality is more elegant. In my case I am wealthy enough to support roughly one person: me.
If I want or need more resources, I have levers I can pull to obtain them. But don't tell me I have a "duty" to add value to the economy.
I won't name names, but I do know people who have simply not filed nor paid taxes in a decade. They even got stimulus checks.
Who is going to create all the value consumed by rent seekers, financial engineers, thieves, scammers, corrupt or bloated government? People who create and provide more value than they consume.
I don't think this is true. This is one of these work ethic corollaries that helped build wealthy societies when productivity was proportional to people's effort. But it seems to grow more obsolete by the day.
Without capitalism, we could regress to the most primitive version of civilization and still require contribution to the tribe. The alternative is to go off on your own (and at that point, there are no "people around you" to help). Less primitive alternatives, as different political-economic systems, usually still require you to contribute through taxation.