I'm not sure I fully agree here. I think for me some level of equality of outcome is what I think would be best. Not complete equality perhaps, but a tolerance band of maximum acceptable inequality of outcome perhaps.
Let me elaborate. I think there should be a minimum level of outcome that every single person in the world should be able to attain with minimal or even zero individual effort. This level should cover basic human rights, plus the ability to live a safe healthy life. For example, the ability to afford food, water, shelter, full quality medical care, clothing, heating, safety, education, childcare, local transport, and having some money left over for entertainment, etc, perhaps some other basics I've forgotten. I would be happy to live in a society that had these things definied as clearly basic minimum requirements and no matter how badly any individual messed up their choices, or even just felt particularly lazy and just decided to stay in bed all day the society would always provide this base minimum level that everyone had available to them, guaranteed. It should be enough to provide for a safe and mostly worry free life. But not so high as to discourage most people from wanting to put in greater effort for greater rewards.
On the other end of the scale, I would be equally happy if there was some maximum level of wealth, beyond which no matter the effort put in no further personal gains could be made. I wouldn't like to guess what level that would be to make sense, although I'm reasonable sure that the existence of billionaires is pretty unnecessary. A progressive tax that at some point around a billon pounds just reaches 100% marginal taxation rate. If you earn further wealth beyond that you are just required to give it all to society.
Let's just say for the sake of argument that my described minimum level was assessed to cost £50k per person per year, and at the top end we were to decide to cap total personal wealth at £1b. What we've done there is introduce a maximum permitted inequality of outcome of 20000x. That is, the poorest person in our society can at the most extreme be at most 20000 times poorer than the wealthiest. This isn't total equality of outcome, we aren't saying everyone has to have exactly equal wealth, just that no matter the difference in opportunity or effort, there is a proscribed limit on the level of inequality.
I think this society would be a much better one to live in. Everyone would be happier knowing that even if things didn't go their way, there are some basics they would never need to worry about.
Equally, once you pass a billion pound wealth, are you really motivated by making more £££ anyway, I don't think it should be an issue for society to pressure those wealthiest individuals to seek other motivation rather than just continuing to generate personal wealth.
(Just to note, I fully understand the difficulty of actually implementing a wealth tax that works like the one I described, I know that taxing income and wealth are different and it would be nigh on impossible to do what I'm suggesting. I'm merely using this extreme example as a way to discuss the idea that some level of equality of outcome is good in my view)