You’re describing an antithesis of podcasting. It was invented for the very reason you’re hating it here, which I find strange.
It’s like complaining how walking has a great advantage on your health as a means to shit on the invention of cars—when cars are invented for people who are not willing to walk (and some other reasons)
Raindrop.io is my go-to. I’ve tried Pocket, Google Keep and Collect by WeTransfer before. And always found myself coming back to Raindrop every single time. It’s great because its free tier is more than enough if you’re looking for “keep track of all the interesting sites/articles” and that’s that. Also, it’s cross platform.
Playing devil’s advocate here. But, I think it can be bad for Spotify if the user copies the playlist that’s being curated by Spotify to another streaming service. It’s good for them if they could add some friction to it by, you know—manually copy it and doesn’t let it update automatically every time they make a change to the playlist—by shutting down the API for this kind of request altogether.
It’s not about “allows user to quickly find the same songs elsewhere”, because if you’re not ready for that then you shouldn’t probably be in this business in the first place.