lightning's source routed model is inherently brittle

i spent last year working on turning this into a network relay protocol like tor... the only solution i could figure out for solving the brittleness problem was by using a similar idea as Atomic Multi Path AMP lightning sends, which are not yet well supported

they basically send the message over several paths at the same time, so they cost a lot more in bandwidth but it's a further step beyond AMPs because AMPs split just to reduce the size of each payment along their respective paths

the equivalent in LN would be where you make the same payment several times and whichever one wins the rest are ignored, but based on the current protocol that would be hard to enforce if two paths win for the receiver to not claim all successful paths

but for data routing it doesn't matter, of course, job done, even if two out of 3 got through that's better than zero out of 3