I hope you take backups - I lost 500 tabs stored in OneTab about 3 years ago. Just launched the browser like always, only to see blank onetab page. It probably wasn’t the extension’s fault but browser’s (I don’t remember whether I was using Vivaldi or Opera at that time), but that day I moved to https://pinboard.in
For a rather fair price ($1/mo.), I get synchronization between devices, link tagging and custom notes (attached to bookmarks or not). I can search everything I entered by full text search (and for extra $1/mo., you can also search the content of webpages your saved links lead to). There is some staring feature (mark as favorite) and "todo" marking, but I never used these.
You can export your bookmarks in JSON, HTML or XML. I have a Python script that takes the JSON export and sends my bookmarks to archive.org's Save Page Now! service https://pastebin.com/uUVE22RD .
The biggest downside is that UI is slower, as obviously a web server is involved. But I like the UX flow provided by BrowserNative's Pinboard extension[0]: Alt+P to open bookmarking page, hit few letters of a tag, hit Tab to accept suggestion, hit Enter to Save, hit Ctrl+W to close the tab.
I have to say however, that my use case is primarily saving stuff "for future reference" or as long-term todo. I still have 20+ tabs open for short-lived stuff. Perhaps your workflow may differ.
What I miss a bit about onetab is the ability to quickly save or restore a whole set of tabs, and how you can open and delete a link in a single click.
