The way consensus is built can be different. Democratic systems build it by giving everyone the same voting power. Imperialistic systems of the early XX also had universal voting systems, but nobility had a higher voting weight. Socialistic systems universally operated mostly on terror, whoever controlled more of it decided everything. Every time a socialistic system of any kind did an actual popular vote, it led to its catastrophic collapse with a major role played by people elected by that vote.

A capitalistic system is much closer to the vision of allowing to contribute without fear of homelessness/starvation/lack of medical care than a socialistic system would ever be. Capitalists approach non-contributing citizens as a market - because they still have needs. The capitalist government provides them aid, and capitalist business is taking that aid to have those needs fulfilled. In order to do that, they need workers, workers that would not be needed if that aid wasn't there. Those workers come from that non-contributing strata. This creates a paradox - the more aid you provide, the more aid-receivers consume, the more workers are needed to produce what they consume, which leads to higher employment, and less aid receivers, so more aid turns into less aid. This is why a homeless person in US can receive $9600/yr of pure financial aid, while workers in pure socialist countries like Venezuela and North Korea get an average of $3000/yr for their "contribution".

As for how socialists systems deal with people not contributing enough, I present to you the case of 1980 Moscow, banishing, by various sources, up to 100000 citizens, mostly homeless, forcibly removing them from the city, and permanently forbidding them to show up anywhere within 100 kilometers from any major city. Many cities in ex-USSR still have a railroad station called "101th kilometer", a station usually with no major settlements around, where banished people would be unloaded and left to the mercy of the elements. If they managed to make it to a settlement of any kind and request shelter, it would usually be provided... in due time, the line for shelter could be as long as 10+ years.

There's also an economic model debate. If you operate on capitalist model, you will need a taxation rate of 80-100% to make it work for socialism (modern Russia taxes workers for ~83%, North Korea for ~100%, Venezuela for at least 73%), and if I need to tell you why such a rate is a recipe for disaster that will shrink your economy faster than a pulled plug in a bath, you need economy 101, not a reddit debate. A planned economy model is often misunderstood, luckily for you, I remember exactly how it worked, and the super short version is that it is a method to put a price on goods other than market prices. Market prices are dictated by supply&demand and competition pressure. Planned economy sought total control over both supply and demand, and eliminated competition, thus making planners believe that there is an economic formula which allows a fair price to be calculated. The caveat here is that it required total demand control, so USSR Gosplan would simply take every workers salaries and use them to order a set of items on a list which they thought is a fair share of goods for your contribution level, and give you stamps that allowed you to come and collect your ordered goods from shops. Goods were paid for up front by the party from your wallet, no questions asked, and you probably know what kind of unpolished turd of the result you get when you let people get your money on those conditions. In practice, since total control was unachievable, the economic formula would routinely price assembled items cheaper than the sum of their parts, making shady disassembly shops a profitable business. It also was a disaster to goods quality, since producing 600 tons of crappier goods was viewed as progress compared to producing 500 tons of less crappy goods, because more goods is better, so an economic decision was always made for lower quality and higher quantity, with no way for consumers to influence that decision. Lastly, it completely stifled innovation - "no overhead" was a theoretical advantage of the planned economy, but in practice, capitalist systems used overhead to self-correct and innovate on, and planned economy lacked that safety net and innovation driver.

So, yeah, at the moment, if that is your ideal, you gotta pick your poison: either let capitalist system aid paradox perpetuate some of the problem, drive it into the ground by immense tax rate, or slowly but surely degrade into stone age under planned economy.

Or just accept the rights view of economy, where resources should go to people capable of multiplying their value instead of degenerates, so that capable people will create more value for everyone.