Think about it this way: bitcoin is censorship resistant, fixed supply money. You can actually own bitcoin and no one can seize it from you.
But these attributes are not free. They come at a cost: 10 minute block times, limited block space, needing to run a node to verify the bitcoin you receive.
Things like ecash are being explored for use cases where people don't necessarily need or want to pay for all the heavy duty benefits of bitcoin, but they want some of the benefits.