Most plans to implement LVT at scale that I've seen include provisions to increase the rate slowly over years and decades, and allow deferred payments for the elderly upon sale or from their estate because yeah, a lot of people made plans to retire based on the present tax regime. Younger people saving for retirement can plan on putting retirement savings into productive assets rather than land speculation. I'm also not entirely clear on why a pension that pays for everything except housing is fine, but providing housing for the elderly is a problematic level of state intervention.

VLC's poor performance in seeking backwards in general, not just by frame, is a big part of why it's no longer my media player of choice. Which is fine! As an OSS project there's no real reason to care about the number of users as long as enough people are involved to sustain the project, and making the developer experience pleasant is more important than making the user experience pleasant on that front. It just means it's not as good a tool for some users as others, like mpv.

I'm quite pleased to live in a country with a decent public healthcare system. It does indeed have some significant benefits. It still has half the problems on your list, and more besides.

Since the directory is titled based on the hash of the various inputs that go into building the package, when I run an upgrade it's not going to overwrite the old version of mpv, but instead it's going to put the new version in the nix store as well, at a different directory. Until you collect garbage, to clear out the old versions of things you're not using any more, nothing is deleted.

So while you can add and delete entries to the nix store, each entry itself is read-only once it's been built, and thus immutable.

For the system itself, each time you run "nixos-rebuild switch" it builds a system out of your configuration.nix, including an activation script which sets environment variables and symlinks and stops and starts services and so on, adds this new system to the grub menu, and runs the activation script. It specifically doesn't delete any of your old stuff from the nix store or grub menu, including all your older versions of packages, and your old activation scripts. So if your new system is borked you can just boot into a previous one.

Transmission through sharing needles we have less confidence around, because illegal drug use is harder to study.

IIRC not everyone reaches an undetectable viral load through antiretroviral medication, so you do need to make sure that's the case. Pre-exposure prophylaxis and general safe sex practices like condoms can mitigate the risk for people with low-but-detectable viral load and their partners.