Yes I am one of the peoples that complained about Discover in Lx 3 from time to time. I have never used dnfdragora so can’t say if it is worse, better, or indifferent. Except for testing I use the command line for package management.
So as far as I can see Discover is working just fine in Cooker/Lx 4.
Before more knowledgeable users complain about Discover it may be worth reading the part of this where they describe what Discover is and more importantly what it isn’t.
I would like to see us try dnfdragora just to see what it is like if it is a worthy replacement. Is it a better GUI for advanced users? Is it different enough from Discover to warrant inclusion in final release? No way to know without trying it. On the other hand if it does not happen at least we have a working tool for users fearful of command line. And they can install official Flathub packages! (I know nothing about Flathub yet.)