Ask HN: Is desktop offline harder than mobile offline?

I have big chunks of working time where I'm offline. I've been looking for a task/note manager like trello but it and all the alternatives I've seen have iOS/Android apps, but not desktop apps. I understand that there might be less of a demand, but I know in the case of Trello, there is a reasonable number of people that want it.

I asked the support of one of the companies today if their desktop app supports offline, and if not when it would. The answer was that they plan to but it's difficult and there are other priorities.

I'm just curious if there is some reason supporting mobile offline is easier than desktop offline?