Ethereum and BitcoinCash are potential cryptocurrencies and have there unique features.
Ethereum uses Smart contract that enables dozens of cryptocurrencies to exist, without having to build their own blockchain technology. Recently Ethereum has upgraded to Ethereum 2.0, which aims to facilitate the communication between the network codes, and is termed as Hobbit. All these developments is making Ethereum better and faster.
On other hand, Bitcoincash after the hard fork as showed quite a good improvement in the market. Recently, blockchain.com introduced a new tool for crypto enthusiasts to get a better understanding of their cryptocurrency. With the recent addition of Bitcoin ABC, 0.18.0 was the latest developments which include instant and reliable payment experience, without needing to change the consensus rules.
According to Coinmarket cap, Ethereum is standing first in terms of Marketcap and circulating supply than Bitcoincash. Also, in my opinion holding Ethereum for long term is more beneficial than BCH.