LN is just a different settlement layer between large entities.
its only "failed" if you expect something else from it.
and if ecash provides BTC denominated custodial txs on top it isnt a problem.
Discussion
If something only works good in a custodial way it is a failed project. If it would work that perfect it would not need a marketing team.
POSIWID (Purpose of a system is what it does)
LN works fine noncustodially if you can deploy resources.
So not appropriate for end users unless you have a lot of time.
but its true it failed to scaling the core principles of Bitcoin