Pretty much by definition in countries with large populations of old people, the current governments largely rely on the vote of those old people to stay in power. This makes the cull-the-herd theory rather unlikely in my opinion. I think simple incompetence is a sufficient explanation.

Also, many of the politician are old themselves. Being in public all the same, the are really vulnerable.

What makes you assume that the economic output of these old people, on total, is negative? They might be holding/running investments, collected massive knowledge along their careers or have enough savings and are making money for the private healthcare system.

If they go away, we might lose on the knowledge or their investments might stop working and the new youth might not manage it any better. So a total loss of society.

Holding/running investments -- investments would be passed to beneficiaries, who should have longer time horizons

Massive knowledge -- retired and not using it

Making money for the healthcare system -- fundamental life science advances could be lost or slowed down, but most healthcare spending is pure consumption, the labor could be better deployed to something more productive

I'll give you a different basis for a conspiracy theory:

China got COVID-19 first. And got over it first. US and Europe are going to be devastated by it. I'm guessing Russia will fare no better. In the aftermath, who's going to be on top on the global scene?

In the tabletop exercise performed at Johns Hopkins just a few months ago, the world didn't fare so well. Even though some countries initially control it, it continues to spread and be reintroduced, ultimately leading to 65 million deaths worldwide: http://www.centerforhealthsecurity.org/event201/scenario.htm...

A chilling, and somewhat likely simulation.

Chilling indeed - but we do have a weapon against that new virus: global lockdown for n weeks to fully eradicate it.

The possible death of nn millions of people is way worse than a global lockdown for a couple of weeks/months.

What's the conspiracy?

China didn't get over COVID-19. They're still seeing double-digit deaths daily and new infections. They're going to see recurring new networks and pockets appear repeatedly. Endlessly if the virus has endured in other countries. They aren't coming out on top of this, especially given the absolutely enormous GDP damage they've already endured.

It’s extremely far-fetched, but I think the implication is either China engineered the virus or at least allowed it to spread, either because they already have a vaccine/treatment, or at least know they can control spread among their population better than other superpowers. Not to mention the power they wield by being the world’s supply chain.