I considered Raindrop.io [1] at some point, but I ended up with Firefox bookmarks. I have an account and the bookmarks are synced. [2]

Mobile app is inferior to competitors, but Mozilla products are trustworthy. [3]

[1] https://raindrop.io

[2] https://www.mozilla.org/en-US/firefox/sync

[3] https://hacks.mozilla.org/2018/11/firefox-sync-privacy