I mean the actual medicine part. When I think about it, there are still no cures for the major things that ail us (e.g. cancer, etc.). China cured that one guy from his diabetes, but I haven’t heard anything beyond that.
The “promise” of stem cell technology from 20 years ago still hasn’t amounted to anything that your average person can get (and there are all sorts of shady overseas places that give ppl “stem cell” injections, but honestly we should have figured out that shit by now).
If you tear a ligament/tendon, guess what, that shit will never heal back to 100%, and the “oh just rest and do physical therapy” shit is annoying because you’re only really working around the problem and not solving it.
On top of that, as you get older it’s harder for your body to heal from injuries, sickness, etc. and I’ve yet to see any legit progress on anti-aging. If your heart is damaged or arteries clogged, I don’t see any way to reverse it.
And after covid, it’s all been fucked. How many people have long covid and the medical establishment just throws it’s hands up 
basically treating an entire segment of the population as though it was a bad crop yield ("I guess there’s always the next batch!!).
And doctors themselves are often the biggest dipshits out there. They are high off their own supply because they’re “smart” and lack the empathy to actually listen to patients. Either they’re older conservative types or younger lib dipshits. And there are so many horror stories about nurses that talk shit about patients. It’s just dismal.
The common reply is that “biology is hard” but honestly that’s a WEAK excuse. So many advances were made in the past, and there are so many more to be made. An actual concerted international effort, unhindered by profit motives and fucking insurance, hospital, pharmaceutical industries, etc. would almost certainly yield results. I mean look at Cuba coming up with a lung cancer vaccine and curing HIV in an infant. Look at China curing diabetes in that one guy. These advances are possible, but honestly they aren’t coming fast enough. If you’re suffering from a terrible disease/ailment, the “promise” of a new drug that still may be 10 years away is just terrible.
So even if we had 100% socialism now with free healthcare, there are still so many things that need to be addressed. I can’t help but think that had the Soviet Union not fallen, we would have had cures for many things. Hopefully 
can do something about this, but overall I’m still super bummed that the future we dreamed has not materialized.
I’ll push back a bit on doctors being left-leaning. In every country that has tried to socialize healthcare, doctors have organized and aligned against it. Here’s an article about it: https://www.vox.com/policy-and-politics/2019/3/29/18265530/medicare-canada-saskatchewan-doctor-strike
If you want to learn more about the formation of Canada’s single-payer healthcare system and how it was influenced by the Soviet model, there’s a good book called Radical Medicine.
I was only talking about the doctors that I know personally. I wasn’t making a point about all doctors. I’m pretty sure they’re not that representative. I’m not sure why I brought it up, as it doesn’t have any statistical weight. I was just trying to give a perspective from the other side. Not all doctors are like that monolithic group of uncaring assholes that OP puts them in. Even if they might appear that way. It’s simply the external constraints that make it necessary for them to act that way. Most doctors don’t choose their profession, because they want to make tons of money and can be mean to desperate people. They’re idealistic and their dream turns into a nightmare - because of unhinged capitalism. With lots of other jobs - bullshit jobs - it’s easy to quit. But as a doctor quitting would mean throwing many years of very hard work around the clock away AND have an immense negative impact upon the patients most desperate for help (and also leaving your colleges (friends?) with even more work). If I’m stopping to be an Uber driver because it doesn’t make me unhappy nobody would get hurt. The societal impact of that would be: “who gives a shit?”
So they are much less likely to quit and have a strong incentive to keep living in that hell. They might not appear to be the nicest people.
I know a lot of doctors too. The point is how people behave & present themselves has little to do with how they actually behave when their material conditions are on the line.