Paper works just fine - but computers have a huge unrealized potential
I used to use paper lists, and can vouch for the efficacy of it. It has its limitations, of course, but it definitely works reliably.
Computers have great potential, but all too often the developers do not go the extra mile to make it as intuitive and simple as possible to actually USE. Apps are often both crude and complicated at the same time, a patchwork of "cool" (needless) features, rigid automation and "rules" that restrict you, and so on - but more seldom the truly simple yet truly powerful features that could help you.
But I think it would be wrong in principle to say paper is better - it is just that really good apps have not been developed yet, and perhaps never will, so there is currently a trade-off.