Can't access documents in the "On My iPad" folder of the Files app when in airplane mode

I just airdropped some videos to my iPad and moved them into the Files app in the "On My iPad" folder. They play perfectly fine there, until I enable airplane mode. When I enable airplane mode and go into the files app, the whole app freezes when I click on one of the videos. If I force quit the app, same thing happens. But, if I quit the app, connect to wifi, then go into the Files app, I can open the videos instantly. What is the deal with that? What is the point of the On My iPad folder if not to store files locally, rather than being dependent on the cloud?