I think the extra step of going into the app switcher is not really an issue. It works for every app, and I actually like that I know whether I'm using the OCR or traditional copy/paste because OCR isn't perfect. When I copy from the app switcher I know I need to double check the results after pasting. If it just did OCR automatically all the time I'd probably be surprised after copying some text and realizing later that there was an OCR mistake in the result because I didn't realize that OCR had been used.
