My [[One Weird Hack]] idea for [[adversarial interoperability]] is that companies should be required to allow re-importing their exported data, with very limited security exceptions (honestly I haven't thought of any good ones, but let's say there are some). Along with existing hand wavey "you can't make the [format proprietary](#proprietary formats TIDDLYLINK" restrictions, this would mean that there would have to be some actual thought put into making the data usable and not capriciously changing the format. That would provide a more stable surface for other tools / companies to work against.

You could argue this would "stifle innovation" but it seems like a company could always just trash anything [[GDPR]]-relevant that got in the way of a desired format change -- the laws are supposed to make it always easier to keep less data around, after all.

I think you could make a case that this is necessary for meaningful consumer choice; I can't delete my data when I switch from photo-storage-provider X to photo-storage-provider Y without losing a bunch of [[metadata]] I'd have to re-add if I wanted to switch back (and in the real case I'm thinking of, that'd be a pain in the ass).