Blockchain, steemit, busy and Cryptocurrency

There are huge number of cryptocurrency available on internet and every day, we have to hear and read name of new cryptocurrency.
But issue is that how we can judge that which currency is better, reliable and strong as even bitcoin has shown fluctuations which is a nightmare for real investors especially those who are not well-verse with information technology, blockchain and cryptocurrency.
Similarly, I can't understand that how steemit or busy.org generating cryptocurrency with the help of members who are just sharing posts especially when mostly members are just copy and pasting posts.

There are no ads on the websites which can help to generate revenue which could be distributed among the members which can attract and make it reliable for members to stay here.
I hope, someone experienced enough will share with us his/her views to make us understand about this all puzzle.

My other posts are

https://steemit.com/busy/@asifmughal/steem-and-busy-worth
https://steemit.com/buys/@asifmughal/skills-vs-no-skills