If you keep trying to use GUI to do what you want you’re gonna have a bad time. The majority of Linux users doing power stuff like this will use the terminal. Because of that, the GUI is unfortunately underdeveloped.
It’s good once you learn it though. Let’s say that tool never existed. I could easily write a bash script to compress images in cbr or cbz myself. Or autoconvert all cbr files to cbz. Or watch my downloads directory for new files and do that automatically. It’s very flexible and empowering if you learn it. Nobody can make a GUI for every single thing people want a script for.
This ignores subjectivity. What is a 7/10 for most gamers could easily be a 10/10 for a specific type of gamer. Rather than focusing on review scores people should focus on the niche of games that they really enjoy.