Once we have push notifications going clients like damus could become nsecbunkers. Then you would just confirm on your apple watch to login and sign things.
Discussion
I still think there are times you would want third parties to sign things on your behalf when you are not online (like a twitter crossposter for example), which is why I think delegation is important. You could just use nsecbunker if you had a node that was continuously on to sign things, but that will be hard for most people and will push people into custodial nostr.
👀