Unfortunately, there doesn't seem to be anything better than Calibre at the moment. (Though, I'm happy to be proven wrong!) Nothing against Calibre, it's functionally amazing free software and it works very well; I said "unfortunately" because the interface is extremely dated and clunky and confusing to operate. Once you get it working, it's very nice though. As long as you never have to go fiddling with it again, because every time you've gotta reacquaint with it's weird UI. Still, it really is the best available at the moment, and it's free so that's awesome.

My favorite way to set it up is using the linuxserver image, which has a web-based VNC built into it, so you can remotely run the app on a headless server and then use your browser to interact with it.

I have Calibre configured to monitor a folder for new stuff I throw into it, where it'll automatically fetch metadata and put it into the database. Calibre also has an OPDS server built in, to which I point a nicer frontend for reading comics. Currently that is Kavita which provides a decent web UI for both books and comics.

Anyhow, I believe you could enter data about your physical comics into the Calibre database, and then view the metadata with something like Kavita, though of course you'd be skipping the reading features.