ocrmypdf with some specific prompts, depending on the source (language, force, etc.) worked for me most of the time. The biggest issue for which I have not been able to find a solution yet, is proper conversion of pdf to epub. I read a lot on my phone, and the inflexibility of pdf format, with the ugliness of "reflow" as the only apparent option to give reading the look of true epub, on phones, is frustrating.