2005 chevy cobalt won't start

Did you check the oil level? No oil means you seize the engine.

The computer system on the car read that oil life was at 70% :/

Oil means. if the oil change intervals 7500 miles it means there is about 5000 miles before it's due for an oil change It has nothing to do with how much oil is in the engine . That's why they put a dipstick on the engine so as you can check your oil level .The only other the car makers could do to IDIOT proof the car would be to install a low oil shutoff switch But with our government might mandate that they do F_O_R is probably right

Ignoring the OIL warning has just turned a good engine into a good Boat anchor

Have a mechanic confirm what is being said here, but it does sound like you’ve run it out of oil and destroyed the engine. If so it’s time for a different car. The cost of replacing the engine in an old LS will far exceed the car’s value. And when you do get another car have someone who knows about cars show you how to check fluid levels and tire pressures etc. so you can look after it properly and not have another disaster.