I know that with TNG, they had to manually remaster every episode into HD and it was a huge pain in the ass to do. Because of that, they didn't wanna go through all of that again for DS9 and VOY and honestly, who could blame them? However, this was before AI for upscaling SD into HD ever was widely available. Now, with the magic of AI look at what someone on YT did when upscaling these scenes from DS9 into 4K! BEHOLD! Look at that! Not bad for an AI upscale right? So why don't they just simply do that for all DS9 and VOY episodes? There's no need to manually remaster them into HD anymore thanks to AI. Granted, the non-CGI scenes don't look nearly as good as the CGI scenes but even those scenes look better than regular SD.