I believe we do need them but only a few of them that is really needed in the long term. Like zilliqa which can help eth to perform in the long term.

I dont know its risky or not...but if bitcoins come to an end suddenly what will we do?
If someone hacks our mobile and get access to our wallet then what will we do?
How much secure are we?
How much secure are our bitcoins?

I thought you will be talking about the movement in the market, anyway security of bitcoin wallets is there already most probably is how the user use it to let it be more easily accessible to the hackers like sharing your password or even opening links that you does not know. Bitcoin is more risky in the price to me and not to the security part. 

I will sell them away and buy promising coins like policypal, stellar, eth and hold them instead.

I don't think there is that fast and easy way of making money in crypto. The biggest underlying principle is patience. Every avenue for making money in crypto demands patience in order to gain a good amount of money. You need some time to study the market trend of a coin before you decide to sell at a certain high price.

There is fast way in making money in crypto but it is also very risky and maybe you need some connections. Do you hear before this term market make where ICO will pump their coins to a high value in one day so if you got the insider news from the ICO or even your friends you are able to take advantage of this.

Crypto is not for risk takers as it may seem but rather for those who are ready to dive deep into a project, study it and base on tangible analysis make feasible conclusions before investing. You cannot enter crypto based on just your risk taking appetite, you need more than that. Study the crypto market, know how it operates and you will make some good money out of it.

Learning is one thing but if that person is not a risk taker crypto is very volatile for altcoins and even the more stable coins like btc and eth. However even you are not a risk taker you can choose to be a bounty hunter which you does not need to be afraid of risking your hard earned money.

I cannot imagine myself speculating the death of Ethereum due to the legacy it has left since its inception. Ethereum going down means more than 500 alt coins going down and cannot fathom that happening. The dip in Ethereum price has nothing to offer than to rise up again and make surges on the coin graph.

I got a totally different view from you. Ethereum just started to gain the fame after bitcoin, the current price that eth is hovering at might be the cause of over bull market from last year/