It’s not like your screwdriver example at all. It’s like saying I already have my nostr private key in my iOS device and I don’t want to paste it anywhere else on any device, Android, desktop, or otherwise. I want the signer app that I have a use on my primary device to be able to sign into any app on any device. You’re obviously intelligent enough to understand this but you play dumb and throw a hissy fit any time someone doesn’t agree with you.

You can keep insisting that every tool needs to work with every other tool as much as you want. It will never be the case. Nostr or not.

I think it's more common then you think. I am in the same boat honesty. It's not just phones but tablets as well. There are a lot of people who have mixed environments. If signers could work like 2FA apps then there wouldn't be problem.

But they are not 2FA apps. Apps require access to them to do everything on any Nostr app. Imagine having a 2FA code for every follow your app is trying to download posts from. It would take forever.