I think non of them have potential to be next Ethereum. The kind of decentralization, security and diversity Ethereum has developed over the past 5 years, it will take them years to reach there where Ethereum is now however,  Matic is using layer 2 solution of Ethereum network and has captured sizable share of market during the past 2 years and its network is continuously progressing. Hence, Matic holders will certainly book good profit in the next Alts rally.