I think they are trying to tackle different problems. The only overlap is both have strong default privacy. eCash is trying to make make custodial solutions less shitty. Monero is trying to be sovereign digital cash.
Pros of eCash:
-Virtually instant transactions
-Extremely cheap/free
-Scalable: much higher throughput
-Potentially more private in some aspect: no blockchain
Cons:
-Custodial: Ruggable
-Centralized issuance that reintroduces seigniorage: Can covertly print IOUs unbacked by any Bitcoin
-Not censorship resistant or permissionless en masse: if the mint disappears, or simply refuses to exchange or redeem tokens, your eCash becomes useless
If you want self custodial, permissionless txs, with decentralized issuance Monero is the way to go. If you don't care about those value props (which imo are major and the whole point of things like Bitcoin) eCash seems better. You can manage your risk by spreading your eCash among different mints, or not holding large amounts, but the risks above will always exist.