I've been using GMB for 15+ years now, and I've never found anything that really comes close.
That being said, I think cracks are starting to show with the lack of development. It's getting close to 2 years since we've had a commit to the git repository, and I don't think Quentin has visited these forums in over a year. GMB isn't currently working on my system due to the GDK-pixbuf update bug (https://github.com/squentin/gmusicbrowser/issues/262) and I don't see this getting fixed any time soon. I'm exploring other applications, hopefully I can find something that can at least partially fill the void.
I hope activity on GMB picks up again, but even if it doesn't, Quentin I hope you're doing well and wanted to let you know how much I appreciate the time and work you've put into it.