Long term crypto currency value?

I have a couple questions about cryptocurrency.

1. Are ICO's the new way to raise capital for companies?

I don't understand how the value of the coins go up over the long term besides basic supply and demand.
Like stocks go up in value because of supply and demand and also the basic understanding that at some point, the company will pay dividends to the stockholders. What's the long term lure for the cryptos?

Lets say SIA, ripple, steem, or any company that is creating something of tangible value, and the company behind them starts making money. What is the benefit for holding these actual coins?