I use email thyself to capture links, snippets and images.
Move them out to plain text files whenever I have the time. These are just text files. I add lines that begin with some keywords like "topic:", "source:" "subject:", etc.
Semi regularly, check these into my git repo and sync then into my nvalt dir.
This way I can search by topic, search by date, find files with no topics, group links by domains, run stats over them, extract links for any topic, download those links into a single pdf onto my kindle, group them by year, find where I get my most interesting links, cache and index the content of the links themselves.
The act of moving from email to plain text to git keeps things in shape without going out of control. I don't care if any of the services or sources are dead, things are backed up in my email + git + devices I use.
I also got pretty good at awk, grep, cut and sort working with this.