Sure, think tanks often take a more purist ideological view than is actually implemented in the real world. But if you look at the direction the developed world has headed since the 1980s, Hoover Institution and similar organizations have been tremendously successful in moving things in the directions they espouse.

In the 1960s, you had governments owning entire industries (state-owned enterprises), and micro-managing private businesses to the point where regulators were telling airlines and bus lines what fares they could charge. In Western Europe and Canada in particular, even though you didn't have "government control over the means of production" you had several countries (such as Canada) with more than 50% of the economy being the government or government-owned enterprises. That has been the "traditional left-wing" approach during the 20th century. Almost everyone moved away from those approaches starting in the 1970s and 1980s. From 1990 to 2000, Canada's government expenditures as a percentage of GDP dropped from over 50% to well under 40%. An entire tenth of the economy was returned to the private sector in just a decade. In Sweden, government spending peaked at almost 70% of the entire economy in 1995. A decade later, it was under 50%. One sixth of the economy was returned to the private sector.

To give a concrete example, licenses to use radio waves used to be awarded by bureaucrats based on their assessment of what was "in the public interest." They would evaluate applications from different companies for different uses for spectrum and decide who should get a license. (That sort of sweeping grant of regulatory authority was common in New Deal-era legislation.) Today, we and most European countries have replaced that with market-based approaches such as spectrum auctions. This has happened world-wide: the EU has issued directives requiring privatization of post offices and railroads. Macron has floated the idea of privatizing SNCF (which would be like privatizing Amtrak here). Denmark's post office is owned by a Swedish company and Stockholm's subway is operated by a Hong Kong company. These are all the kinds of policies advocated by Hoover Institution and other outfits.

You're also arguing to a degree against a straw man. Hoover Institution isn't some anarcho-capitalist outfit that advocates getting rid of the government. To use your universal healthcare example: Hoover Institution isn't suggesting to eliminate universal healthcare. But there are many different ways to implement universal healthcare. At one end you have the UK system, where the government employs the doctors and runs the hospitals. At the other end, you have systems like Switzerland's, based on mandatory private insurance.

Hoover Institution does not propose eliminating universal healthcare. Their focus has been on the cost inefficiencies created by using insurance to pay for routine medical care. Since at least the early 2000s, they have been advocating an approach that provides universal insurance coverage from the government for catastrophic medical care. But routine medical care would be paid for through health savings accounts (HSAs), where costs could be subject to market competition. Even if you don't fully agree with that approach, there is something to it. It's hard to ignore the fact that procedures that aren't covered by insurance are vastly cheaper: you can get laser eye surgery for a couple of thousand dollars per eye, while simply putting a broken arm in a cast costs insurance $2,500 on average. You don't even have to go Galt with that approach--the government could deposit money into the HSAs of low-income people to pay for routine healthcare. That would still preserve the benefits of market competition for those services.

No European country is going take away "universal healthcare." But, especially as social welfare systems get strained by aging populations, I can totally see countries adopting some of these ideas. Sweden recently partially privatized its social security system. Could they start moving some routine medical care into an HSA-type system with subsidies for lower-income people? It's totally plausible.

Likewise, European countries are currently experimenting with Universal Basic Income. One of the early proponents of that was Milton Friedman, a long-time Hoover Institution Fellow. The idea behind UBI fits the ideology. If you're going to spend government money on welfare programs, it's better to just give people money that they can spend in the marketplace instead of creating government departments and hiring government employees to provide services. I wouldn't say Hoover or similar organizations have a universal consensus in favor of UBI, but there are many in these organizations actively advocating in favor of it: https://news.stanford.edu/2018/08/08/stanford-scholar-explor...