Fair enough on the closed source thing!
My take is that we have specialist requirements for photos that are probably better served by a photo specific UI. Lightroom's doesn't inspire me to say it's great, but it's adequate. Can search by metadata like camera or capture date, save previous search results as 'smart folders' (e.g. I have one for all pictures since I last had a book printed). It indexes thumbnails for quick scrolling. My ancient version doesn't do geosearch but maybe later ones do. You can clone pictures (like a hardlink) rather than copy into different albums. You can also clone pictures but apply different non destructive edits to the same source file. Almost all the edit operations I want are close at hand. Order is preserved in albums. Rate photos 0-5* and tag with different colours. As to how all that is organized, I'm sure it could be improved on.
I've also yet to see a good photo solution for my parents who (like many non tech folk) still struggle to understand folder hierarchies and where they saved stuff. Picasa used to be ok-ish but discontinued. Google photos is a bit of a pain over their ADSL.
Good luck with it anyway!