You describe a capitalist society with advanced universal healthcare and other such services. That’s essentially Scandinavian model, and it’s valid to want to go this route.
Socialists would disagree that this is the best for a variety of reasons.
First off, in defense of socialist regimes, while some select socialist societies did face deficits, sometimes famines even, this came as a result of aggressive and experimental policies (something we now know shouldn’t be done) and poor reporting (something we now have the technology to avoid), all while for most of their history socialist societies did not have issues supplying people with variety of food and necessities. Also, economic issues of socialist countries come as direct consequences of restricted trade with capitalist societies which at all times held the majority of GDP - simply because most countries, especially rich ones, never turned socialist. When the socialist countries reverted to capitalism, they got access to that pool of foreign investment again, boosting their economy. Should it have been in socialist block, tides could turn way differently.
Second, capitalism is not and cannot be sustainable. As it dictates profit everything be damned, we end up with broken ecosystems, clearly broken timelines for ecological transition and continued destruction of our only habitat for sweet sweet bucks. Regulation only gets you so far, as it does not affect capitalism’s fundamentals which immediately manifest themselves once the loophole is inevitably found (or made).
Third, as the main driver of capitalism is accumulation of wealth (which is why people make enterprises in the first place), this inevitably leads in money going into less and less hands as billionaires report ever higher profits while the rest of us is told that some sort of “crisis” is taking away our money, rising costs and deteriorating our quality of life.
Fourth and final, as I told about foreign investment, with modern multibillion international corporations we got into a situation when not companies are fighting to be hosted in a country, but rather countries compete to host corporations, often comprising a significant part of country’s GDP. This reduces the amount of taxes, for example, that a given country can squeeze out of a company in order to actually fuel all that universal healthcare and other services you’d like to see.
So, to wrap up, socialists recognize there is middle ground, more control over capitalism, and should absolutely push for it. Socialists just don’t think it’s enough to prevent economic catastrophes of the future and struggles of today.