Acrobat Reader DC has not been abandoned and probably won't be for many years, as it is the latest version. Adobe will probably support macOS 10.13 High Sierra for at least another two years. So you should be good for another 2+ years.I am on High Sierra. It was recommended that I update to Acrobat Reader DC. So I do not know if it has been abandoned, but it is critical to fill out forms. So am I in the same non-security basket?