Besides the content, this web page design itself is interesting, with dramatic use of color, empty space, and typography.

What alternative solutions does the HN crowd recommend to Google Photos etc?

I'm the author of PhotoStructure. I started working on it to clean up the digital mess I had accumulated due to failed/cancelled photo management software, not to replace Google Photos:

https://photostructure.com/about/introducing-photostructure/

Since then, I've been working on improving deduplication, scaling to very large libraries, and whittling away at the feature list my users and I collaborate on. I keep detailed release notes here: https://photostructure.com/about/release-notes/

Replacing at least the organization and sharing aspects of Google Photos is now my top priority. Improving search (with geo and faces and ML object labelling) is my next.