Extremism is also the problem, because it allows economic systems to be taken to extremes, which become unbalanced and that then unbalances other systems, like the political systems, which when given the right push by a particular aspiring authoritarian can easily end up landing on authoritarianism.

The middle ground is usually the safest place to be. Socialism and capitalism are economic tools, they both have their place, for certain purpose. Extremists would tell you one is strictly, absolutely, and universally better than the other and imply that thus we should only ever use one system for everything (usually without strictly, absolutely, or universally defining what "better" actually means, because it's usually a pretty self-serving form of "better"). That is an extremist position that many capitalists take, and most of western society spent the last oh, hundred years or so believing to various degrees.

Socialized medicine is perfectly sensible, for example, and that's a hill I'm perfectly willing to die on (but because I have access to socialized medicine I probably won't have to die, and I won't be bankrupted either, hooray :P)

Socialism is not perfect, but neither is capitalism, neither is democracy, neither is pretty much anything. Perfection is a myth. There is no perfect tool, not in a workshop and not in a civilization. Some are more powerful than others. Some are more dangerous. Often the most powerful ones are the most dangerous. That doesn't mean they are bad, but it does mean we must respect them and use them with care and attention, and only when appropriate. We don't have perfect tools, and we probably never will but we can have a large and growing collection of tools we can use to manage our lives, our society, and our civilization. The more tools we know how to use safely the better. Only using one tool for everything is a stupid way of doing things, and it can be dangerous in its own way.