I use CoMaps for this. It took a little bit of time for me to get used to it but I now find it so much better than Google Maps bookmarks and I have moved everything over. CoMaps allows a wider range of pin colors and you can add detailed descriptions with each bookmark. No automatic cloud backup but I just export a backup to Proton Drive every couple of weeks or so, takes less than a minute to do so.

A useful app for this task is Geo Share. Helps opening links from Google Maps in other open source map apps.

Good luck finding your solutions!

Like osmand or comaps?

obsidian seems to have a maps plugin

On organic maps and it's forks, you can create bookmarks lists and add places to them. You can then hide, edit, export lists as you wish.

Never tried this, but it was in a selfh.st newsletter a few weeks back

https://www.dedicatedcode.com/projects/reitti/?ref=selfh.st

I thought I would try it out when I had time. It does ‘memories’ and seems to tell a story about your data.