There are lot of crypto currencies that were created to compete with BTC
BTC lightning network is implementing due to the scalability issues the chain is experiencing with high 'fees' and transfer times..
If lightning network is implemented in Bitcoin will it destroys these competitors?
Linghtning is created to help solve some of the existing problems of BTC. Lightning can be used to achieve fast transfer of BTC, small amount transfer, and ultra-low-cost handling fee. This is a very great thing. As for whether Altcoin will be shocked by this, I think this is an obvious problem. Altcoin, which is false and has no practical use, will certainly be affected, but not all Altcoin will face the same problem.