Or maybe instead there are a huge number of views somewhere in the middle. Like, maybe a stable society is one that both rewards individual achievement while trying to maintain a level playing field and providing a basic level of support for everybody in society.

I don’t recognise your mischaracterisation and this sort of thinking is why we are presently so completely fucked.

There are certainly public/tax policy sets that could serve both: to help and/or protect those who don't have the opportunity or ability to become an Ayn Rand hero, but also still allow for those that choose to fight down that path. Yes that means that the richer one becomes, the less they take home as a percentage of their gross (more so than current tax policy requires). But it means that there are more than two extremes to the issue.

The Marxist brigade? Even a pro capitalist should be against increasing wealth inequality.

A healthy market has plenty of competition and competition reduces profits. If the vast majority of wealth gets concentrated into relatively few people then that indicates a lack of competition and leads to inefficiencies.

Every billionaire or mega corp is a market failure

The "market" inevitably leads to conglomeration and monopolization.

It's the natural state for the bigger entities to devour the smaller weaker ones and grow.

That's the reality of an in perfect market, but it's not something that anyone other than the owners of the large companies want