Discover is probably the worst app in the entire KDE suite. It's the only aspect of the Linux desktop that frustrates me, and I'm nearing 10 years of full time Linux desktop usage.
Oh, you accidentally opened Discover? Now you gotta sit and twiddle your thumbs while it updates/downloads a bunch of stuff very slowly with no way to interrupt it. It also locks the system package manager, so you literally cannot do anything else package management related until Discover slowly decides to finish doing something you never asked it to do.