https://aeon.co/ideas/fascism-was-a-right-wing-anti-capitali...https://en.wikipedia.org/wiki/National_Socialist_People%27s_...
https://en.wikipedia.org/wiki/German_Labour_Front
"The Nazi social welfare provisions included old age insurance, rent supplements, unemployment and disability benefits, old-age homes and interest-free loans for married couples, along with healthcare insurance, which was not decreed mandatory until 1941.[8] One of the NSV branches, the Office of Institutional and Special Welfare, was responsible "for travellers' aid at railway stations; relief for ex-convicts; support for re-migrants from abroad; assistance for the physically disabled, hard-of-hearing, deaf, mute, and blind; relief for the elderly, homeless and alcoholics; and the fight against illicit drugs and epidemics".[9] The Office of Youth Relief, which had 30,000 branch offices by 1941, took the job of supervising "social workers, corrective training, mediation assistance" and dealing with judicial authorities to prevent juvenile delinquency.[10]"
Nazi's are the source of many of todays social accomplishments. They may not have been the originators of old age pensions, but they were the first to bring them in on a large scale. Pensions for disabled, same. Rent-control, social housing, ...
And while the NSV was disbanded and recreated from scratch (it still unofficially exists, especially outside of Germany), this is not true for various social welfare organisations in Europe, who find their origins ... with the Nazis and were never disbanded due to lack of alternative (lack of alternative because the Nazis disbanded every other welfare organisation whenever they got a chance, but still. Also the Nazis disbanded welfare organisations by making them part of the NSV and absorbing them into that organisation. If one is truly honest, this was generally an improvement until 1943 or so. And while European states were keen to take control of their local single welfare organisation, they weren't keen on splitting it up again).
It doesn't stop there. As is well known, the Nazi state was not friendly, at all, to capitalists (in fact this was one of the main supposed problems with the Jews. Early on the enemy was "Jews and Bankers". Not exactly laissez-faire rhetoric ...)
Currently the general explanation is that when it comes to extremes, extreme-left and extreme-right aren't actually that different. It is moderate left and moderate right that have a big gulf between them. (extreme and moderate by 1940's standards, not today's)
Unfortunately while the Nazis were an unparalleled evil in history, the world isn't so simple that that means they only did bad things. One might even say that both the war and the endlosung were, at least, partially driven by desperation on part of the Nazi government. Desperation, because their social welfare state was fast collapsing. Nothing can justify the choices they made after that (to, for instance, kill off the "worst" of the disabled, even children, as a cost-saving measure). But if you want to build an argument that they were forced into those choices, it's not going to be very hard. WW2 and the Holocaust kept Nazi's in power for 5 years or so longer than they would otherwise have been. It was a choice between war and atrocities or losing the state that was providing food, loding, and everything for close to half the population.
Obviously the modern left does not like to call attention to that USSR and Nazi (and other) atrocities happened, in some small part, to enable social welfare. It may not be a reasonable criticism of today's policies, but anyone can see too many people will see it that way. I shudder to think how Trump would use this argument. And we all know, if it was the least bit popular, he would.