On iOS you can create a shortcut to push a screenshot through the built in OCR and copy to clipboard. You need to crop beforehand if you don’t want all the text on the screen.
On recent iOS versions it just happens. You try to click on an image in the browser to save it and whoops! you're clicking on text in the image that iOS already OCRed for you. And the Photos app will let you search for OCRed text, and it OCRs _all_ the text without you having to lift a finger.