For the most time I just kept tabs open or used the post save feature in Reddit, Mastodon and Lemmy. That way I collected dozens if not hundreds of things that were vaguely interesting but I never got around to looking at them anyomere and when I was looking for something specific I had to check multiple places, each with less than optimal search functions.

Last year I decided to just create a personal wiki. MediaWiki is FOSS, easy to set up (especially with docker), accessible from all my devices and has a huge community because of Wikipedia. I have specific articles for different topics:

• a list of things I might want to buy at some point
• lists for books, movies, shows and games I want to read/watch/play in the future
• a whole category of cooking recipes in a format that's more readable than the original versions where you have to scroll through ten pages of the author's life story, translated into my native language and with notes on what I changed from the original
• articles for projects or questions that I never quite solve ("Where to buy custom printed LEGO minifigs?", "What scripting languages are easy to embed in a C# project?", "What's that weird bug that causes zfs to throw errors when my HDDs take a bit too long to wake up from sleep?") with partial answers.
• articles about my friends with some basic facts like birthday, favorite color, favorite animals, allergies and things we'd like to do together at some point
• and many more

Whenever I find an interesting link, I check if I already have an article that it fits into and if not, I create one. That way everything is roughly grouped by topic, I can leave notes and I have a nice search function and even a history that keeps references to stuff I edited or deleted.

Edit: the downside is that saving a link takes a bit longer, especially when I'm on my phone. Because of that I occasionally still save links the way I used to and if I still think they're relevant after a few days, I move them to the wiki.