What you are describing is not about capitalism or other systems, it's way more fundamental than that. Youre describing having two conflicting need, scarce resources, and limited time: "spend a week generating resources I save for the future" vs "use saved resources while I care of a sick loved one this week" - whether the former one here is working on your own farm, building your own shack, volunteering at the community center (to "earn" social trust), doing a task for someone else, or going to a factory to get paid for hourly labor.

There's no escaping the fact that one (or a collective) must generate a surplus of energy to store if one wants to be able spend any time NOT merely generating energy 100% of their time. Either that surplus is owned by individuals and they're free to generate it and use it how they see fit, or it's owned by some collective entity. In the latter case, some system for the contribution, distribution and physical protection of the shared savings is required - and there's no way to make those systems in such a way that's fair to all and not liable to capture and prone to violence.

You're not critiquing capitalism, you're upset at the existence of the fundamental mathematics of scarce resources. I agree - it's a bummer that we don't have infinite resources. But we don't. and we have to find the best way to handle that fact in a way that doesn't result in constant conflict.

For what it's worth, technological development driven by the engine of profit-seeking capitalism - stunted though it is by State intervention - is brining about the closest thing we've ever seen to "infinite resources". Quality of life goes up while prices come down. A smartphone from 10 years ago is basically free now while it was mind-blowing when it came out. Strangers can have conversations about capitalism across the globe at light speed without censorship. A relatively "poor" kid by today's standards can start a podcast nearly for free... We should expect this to continue to the limits of physics - IF we let it and don't fuck it up with collectivism. You want your infinite resources and perfect equity? Embrace progress and private property.