I have been using raindrop.io for years now, and it has worked perfectly for me. Seriously, no issues.
But, bookmarks are something that are a bit too personal... they allow profiling you. And I don't want anyone doing that to me,
Hence, this app. It's 100% offline and free.
It's built in Rust using Tauri, is roughly 6MB only, is beautiful to look at, and packs more features than commercial ones.
Make sure to checkout the "All features" page as well from the homepage.
Also, it has an inbuilt api server (configurable) so you can automate as well, for example, from your agents, or build a bookmarking browser extension. Checkout the api reference from homepage.
Code will be open-sourced in a few weeks.
Syncing server, to sync across devices, is also coming. Of course, that will be open-source as well.
PS: I was unable to test on Linux as I don't have that system. In case you find any issues, please mention in comments.
Thank you..