Over my life I have found that with any Apple technology it may work great with anything outside Apple's control... Until it doesn't, usually out of nowhere.

My father is mostly on Apple and tries to use his iPad as a PC, ie with files and "the filesystem", he tries to get out of using extra iCloud for pictures (using Proton, or he asks me about Immich, or he wants to use an external HDD, or use Synology Photos and backup). He's mostly on the iPad + keyboard because it's a nicely managed device update-wise and "what I can install"-wise, virus-wise.

But I recent told him: Just give up. Buy (rent!) the storage, you are too depended on me, there is always something with the non-Apple solutions. Yes, your iTunes library is a mess on the filesystem, just don't look at it through anything else than "Music". Yes, Proton Drive eats 400 GB of your iPad storage now, I don't know how to trim that regularly. I'm sorry, it's either Linux and I can help set some things up, or full Apple. Choose. His current mixed, "trying to get best-of-both-worlds", approach is just pure unexpected pain, every time again.

Edit: I also have an iPad, it does work for me, but where my father is trying to use his iPad as a central, primary device (the hub), for me it is a client (spoke) of my own infra. Apps get access to information and I never use Apple services for anything. So indeed, Immich, Proton, Home Assistant, government and banking apps, etc. My iPad is throw-away: If it dies, it dies... I buy a new one, log into all (self-hosed) services and I'm 100% back up and running. Doing the same for my father is also pain, because his Home Assistant will have issues, or his Immich instance, and it's real work to fix, and he won't tell me for months if it does not work and work piles up. So, I tell him to surrender to Apple... It die a little inside.