> What useful product did Enron ever build?

Electronic trading platform

Enron Online, launched in 1999, allowed buyers and sellers to trade energy-related commodities like natural gas, electricity, and broadband capacity.

Gas Bank

Enron's Gas Bank stabilized prices, making natural gas more attractive to investors and helping lenders finance new gas generators.

Financial markets

Enron created financial markets for assets that were never previously traded on exchanges, such as natural gas, coal, and internet connections.

Power plants, lots of them. Then they hired Wall St MBAs who thought executive compensation should be based on how well they can pump the stock. Sounds a lot like Tesla come to think of it.