Why pre-Bitcoin cryptocurrencies failed?

You can be intuitive and presentable. Use text, image, illustration, table, whatever you feel suitable.Note: you don’t necessarily need to understand how cryptocurrencies work. That’s part of this course and we’ll study that later. Just gather useful information on the reasons behind the failure of earlier cryptocurrencies. This will give us a good background of why and how blockchain got developed for Bitcoin, which hasn’t failed yet.Look at slide 6,7 of the attach slides to know what is different from bitcoin, and compare it to crypto currencies that were created before bitcoin like eCash, B-money, Bit Gold, Hashcash and why they failed and Bitcoin didn’t. you can also view this link for the white paper of Bitcoin. https://bitcoin.org/bitcoin.pdf