fork coins can never become successful in the long run because they can not offer any real usages. it is simply due to the fact that they are mere copies of the original project which is doing everything they do in a much safer manner.
also keep in mind that they are going to be competing with a lot of altcoins that offer better usability than them.
Agree. Most forked coins are copies of the original Bitcoin blockchain with some minor modifications. They don't provide something unique that's innovative from the rest of the cryptocurrencies on the market. As such, people would see no reason investing into these coins, as they merely serve the same purpose as Bitcoin. Of course, Bitcoin Cash has been claiming to be the true Bitcoin for a long time. On the other hand, Bitcoin SV claims to be the original Bitcoin.
But at the end of the day, none would be able to provide the level of adoption, development, and support, Bitcoin has been giving to the world for a long time. Comparing BCH and BSV vs Bitcoin, they're highly centralized and relatively unstable. Bitcoin has far more security and reliability than both BCH and BSV combined, not to mention that it's decentralized, and no single entity oversees the future direction of the cryptocurrency. BCH has Roger Ver and Jihan Wu on its side, while BSV has Craig Wright and Calvin Ayre on its side. On the other hand, Bitcoin has no public figure, and everyone is on its side. There's never been a "Hash War", neither dangerous block size increases that would compromise the whole blockchain.
Which is why, I believe that Bitcoin would succeed in the end with its Lightning Network. It's the most decentralized approach yet for scaling (although not completely decentralized) that would enable anyone in the world to process transactions without requiring a high degree of storage and bandwidth for full nodes (unlike increasing the block size). The main chain could operate the same way as it is right now, while the LN (being a Layer-two solution) would take care of micropayments in an easier way.
Nonetheless, what the future holds for both Bitcoin Cash and Bitcoin SV is quite uncertain. For what I know, BCH and BSV's price combined is lesser than BCH's price prior to the hard fork on Nov 15th. That has a lot to say, as it could mean that investors have lost confidence in BCH and BSV. Just my thoughts