Don't you think a full web app is something different than a webpage?

I think there should be options, that are opt-in

Alt-d on my browser adds a Bookmark. I see no problem in hijacking that shortcut.

Are you everyone?

That is only one example of a shortcut which doesn't work.

There is ... another.

F6

that's good, but it's also more movement than alt-d which I can do one handed without moving.

That was just one example anyway, other shortcuts are blocked too