He already admitted the *major* difference. 
One requires trust in a custodian (ecash), the other doesn't (Monero)
It's can never be a full replacement for Monero because of that.

That being said they each have their own unique advantages. For instance, ecash is: instant, free to transact, and can be used offline. 

Different tools and use-cases.

The Monero "debasing" Bitcoin part makes zero sense 

 By the way, you can also have Monero-based ecash. There is someone already potentially working on it.

https://njump.me/nevent1qvzqqqqqqypzqmajvcqjcvqgxql9ftj4zs95d9t7n9uqnpqpmk357nvjrgn4h79mqyw8wumn8ghj7mn0wd68ytnsdae8getddahx2un09e3k7mf0qyd8wumn8ghj7un9d3shjtnndp5hgen0wf3k2tn0dejj7qpqqeraqwjgqv7an4l28pz4wtwvxeg4swrwyx7gmat7k45gfsysdggstfxxdq