There are so many out there, a few that I came across include:

• Wallabag ( GitHub, Website): Older, long history, somewhat clunky now?
• LinkWarden (Website): Focus on multi user and teams?
• Raindrop.io (Website)
• Omnivore (Website)
• Hoarder (GitHub)
• Shiori (Article)
• Readeck (Website)

Having a giant comparison table for this might be nice