> Population

Projected to stop growing this decade and go down, with many fist world countries staring the barrel of socioeconomic collapse due to lack of new births to grow into the workforce to sustain the outsized outgoing aging population, while developing nations are seeing population booms that they cannot sustain as a result of many of the easily extracted resources already being plundered or polluted (Fish, Clean water).

So many of the countries that are losing are projected to soon start losing population (To name some big ones, Japan, South Korea, China countries and if US immigration faulters, USA as well) and face a demographic retirement crisis, while many of the countries that are projected to (keep) gain(ing) are doing so without the access to resources to acquire them.

You need blinders to look at the current population demographic and think "Yeah, this everybody is flourishing, this is going to work out great"

> Kardashev Scale

Not taking this seriously I see as we don't even rank, We're over 5 orders of magnitude from the first threshold, so it's not even like it's close. So a meaningless suggestion.

> literacy rates

No argument there, but if basic human literacy is "flourishing" to you I see the bar you've set and I've set for "Flourishing" are as stark as "Alive" and "Dead".

> sexual equality

Those rose tinted glasses are polarized as fuck

> the very definition of poverty

The goalposts they keep moving so that less people than ever qualify so as to appear as poverty rates have largely remained stable instead of ballooning 3 fold in the US as they slowly squeeze the middle class out? Yeah. Real Flourishing.

> per-capita frequency of violent death

Fair point here too, Has been on a general decline in the 2000's, and too soon to say anything about the 2020's. The first thing you've listed I'd agree as actually "Flourishing".

> great-power war frequency

You mean the continuous Great Power Proxy struggles that have killed millions with regularity across the world, forcing non-great powers to suffer the evils of war while those great powers sit back in comfort and throw shit at each other on twitter/TV/Newspapers? Yeah. Really flourishing. That MAD policy was a reaaaal step forward for life on Earth.

> vaccine and medical sophistication

Hey, another one you slam dunked.

> education rates

You seem to keep repeating the mistake at looking at averages of people that are just "educated" and not looking at the level of education. More people recieve AN Education today than ever before, even as a percentage of population, true, on a global scale. However, general performance across the board has been on the decline, as have academic and journalistic standards and integrity. From China to the US, the education systems are doing a worse and worse job of educating people, despite churning out more white papers and degrees than ever.

> patent filings

lol no. This is like measuring a mobile phone platforms app stores success by how many apps it has. If it has 100,000 shitty flappy bird clones, but no weather, social media, entertainment, finance, or other very common tools, that doesn't mean it's good or flourishing. People flooding the Patent office with bullshit just to compete on "Patents filed" is Cold War era childish oneupsmanship. Quantity is Not Quality.

> Much of the hand wringing arises precisely from the fact that we don’t want to lose what we have

Yes, and their wringing their hands because they're losing it. It takes a cantankerous set of blinders to look at everything they HAVE and assume it'll just continue being that way.