Advertising.

Cars are too prevalent in most countries, but they are undeniably very useful when used correctly. I would probably say the social media does more harm than cars, but idk if it's the worst invention. Lots of candidates.

It's a three way tie between:

• Leaded Gas

• Aerosols

• Nuclear bombs

Religion. So many of today's issues stem from the magical thinking inherent in religion.

24 hour news networks.

News used to just be the news when there was a half hour of local, half hour of national twice per night with a morning show for fluff, weather, and brief news updates. 24 hour news needed to fill the whole 24 hours and also pay for itself by getting eyeballs on advertisers. That’s when all of the sensationalist stuff started taking over.

Slavery. Even after banning it pretty much everywhere, people still find ways to treat others as disposable property.

Shareholders.

nuclear weapons, too feckin dangerous to have

Head on! Apply directly to the forehead
https://youtu.be/Is3icfcbmbs

The wheel. Everything went downhill from there.

A financial system that breeds billionaires

Religion

It's likely LLMs in their current corporate circular funding form and cryptocurrency.

Disposable vapes come to mind, although the real answer is probably some extremely depraved torture device.

So far crypto currencies. So far they seem to expend a huge amount of electricity and used mostly for speculation.

Social media year over year shows it was a mistake.

Teflon

Either leaded gasoline or pfas

Easy question:

AI

Net negative pushing us toward unavoidable global ecosystem collapse: it produces nothing but the unfulfilled promise of eventually replacing human workers, which it has never shown the capability to do and according to the researchers who founded the AI companies will never do due to "AI Scaling Laws". It has increased power consumption and costs by over 30% in some US States.

industrialization.

it's caused unfathomable damage to us, our planet, and the organisms we share our world with.

it's also saved just as many as it's harmed, but there is an upper limit when our planet dies and we all die with it.

Lead pipes.

Leaded Gasoline comes to mind...

Leaf blowers. They solve nothing permanently, it just moves around the leaves, meaning the blowers will be back again tomorrow morning, waking me up...

[Gestures broadly to Thomas Midgley Jr.] [Link]

Meta

JavaScript

Money

Coffee pods. Just when we were getting close to maybe reduce or reliance and dependency on plastics BOOM! coffee pods everywhere, by the trillions.

Plastic.

I think it has to be something that poses an existential threat to human life on this planet, so cars (and other inventions dependent on fossil fuels) is a pretty good pick for the top of the list, IMO. I saw someone in the comments pick animal agriculture, and that, too, contributes to the existential threat of a warming planet; so that, too, feels like a good pick for the top of the list.

For me, though, nuclear weapons has to be the worst thing we've ever invented. No other invention is capable of ending human life on this planet so quickly and so thoroughly.

Market speculation or quarterly profits.

Weapon of mass destruction

Me.

The corporation.

Greed

The 40+ hour work week.

Money.

Property ownership

Waepons!

Agriculture.

We could have stayed in a world where we lived in harmony with nature instead of trying to control it.

Roads

Marketing

Chemical weapons

I know this will seem trendy, or whatever, but AI and social media have been the worst inventions since religion.

Profit.

car alarms

Humans

Guns and other weapons

loans! They simply jack up the prices and help separate the haves from the have nots