The poor is having increased living standard overtime: toilets, electricity, AC, refrigerator, TV, etc. etc. Why? Because the rich invests in technology and the poor takes benefit from technical improvements and successful business.
We are living in a sad state where everyone is benefiting from technical progress but people think only the rich is benefiting.
We live in a sad state where people expect everyone to be happier if absolute material condition is improving despite the gap between haves and have nots widening, because everyone either ignores or prefers not to believe the piles of evidence that, outside of the most desperate circumstances, relative deprivation is the main driver of experienced disutility, not absolute condition, so the people with power (including the relatively empowered portion of the electorate) keep pushing full throttle on policies which make human experience worse while looking at poorly chosen metrics that let them say things are getting better.
The most common practical argument that I've heard is that not doing so will cause those experiencing that disutility to take matters into their own hands, which is:
1) risible, to the extent that it is untrue, as slander generally is, and
2) unconvincing, to the extent that it is true, because it's a trivial case of extortion, and the correct game-theoretic answer to extortion is "no", and is also immoral for the same game-theoretic reasons.
I'm curious if you have a more convincing argument, along any dimension. n.b. My prior is that such redistributive efforts are long-run harmful in expectation to material conditions at all levels of the economic ladder, possibly with the exception of revenue-neutral taxation of land value & externalities (which may or may not end up being redistributive in the progressive sense). If you disagree with that, there's obviously an argument that could be made on that basis.
Things increasing in absolute terms isn’t improvement in and of itself; improvement consists in, and only in, enhancements to someone’s experienced utility.
> I'm not clear on what the (moral) argument is for acting to mitigate it on that basis.
The moral argument depends on the moral principals you subscribe to. With utilitarianism or Rawlsian liberalism, the argument is fairly trivial. In the moral framework of, say, Objectivism or Austrian economics there probably isn’t an argument, but the very idea of measuring aggregate outcomes to assess progress in those systems has no direct moral relevance, its just a way of redirecting complaints from people with different moral frameworks. The whole theory of appeal to broad aggregate measures is as an assumed proxy for broad experienced utility.
Also, people's experienced utility is not solely a function of positional concerns, so the claim that things increasing in absolute terms isn't an improvement (in terms of experienced utility) seems trivially wrong. To the extent that it's a useful claim you could say the same thing about reducing inequality; there's nothing inherently good about that, except to the extent that it improves experienced utility. So that circles back to the questions of "which factor(s) have a stronger effect on people's experienced utility on the margin", "what 2nd order effects (including feedback loops) might occur due to our proposed mitigation", etc, which ultimately boils down to an empirical question about whether people will gain more (long-term) from absolute improvements on the margin or from positional improvements on the margin. Economic growth compounds, so sacrificing it as a temporary band-aid (that might make the underlying issue worse!) before we've even reached "fully automated luxury space communism" levels of wealth seems like a sucker's bet.
Historically speaking, capital didn't dig the coal out of the mines -- it bought the equipment and collected the proceeds, passing on the wages, but it didn't do the digging. That was Labor. It didn't fill its lungs with coal dust, that was Labor. It didn't even properly fund the retirement plan it promised in exchange for work -- Labor had to pick up the slack. Ditto for career risk. The company discharged responsibility for its piles of tailings in bankruptcy and the government had to pick up the tab. The long dead company certainly won't pay to clean up the CO2 it pumped into the atmosphere, that'll be on our children.
Capital is always trying to take credit for everything. That's what they're best at, it's what they do. They always try to minimize the role that everyone else played in making things happen. We shouldn't let them. Capital doesn't even do a very good job of fulfilling their nominal purpose, which is to shoulder risk and responsibility: they offload it at every opportunity, often successfully. We are on the other side of that hustle, so it's important to not let them get away with it, because they are always trying to privatize the gains and socialize the losses. A moment's negligence will let them get away with it yet again.