WHY WOULD USE SUCH THING AS ECASH?
The situation with Bitcoin (BTC) and Lightning Network (LN) right now, is not favorable with onboarding billions of people, that are not well prepared and this situation will get more complicated until we could find more practical and easier solutions.
Yes, some old bitcoiners will not see any advantage of using this ecash, other than adding some more privacy on top of the existing LN protocol. Those that have already a lot of liquidity in LN channels and various UTXOs in cold storage, this use case will not bring them too many advantages, except if they want to use ecash as a form of coinjoin their income sources. But that is another story.
But for many new Bitcoin users is quite hard to get started with a UTXO directly onchain and from there running sophisticated LN nodes, public or even private nodes. Managing LN liquidity is not so easy for many new users. Yes, they can use a large number of custodial LN wallets / accounts, but those also still could leak a lot of personal information and easily be shut down or limiting access to users funds.