I know where you’re coming from. I too dream of such a second brain–the one place to collect everything I want to remember in, and take a bird’s eye view of my second brain in a grid layout.
You might want to take a look at mymind and raindrop.io:
If I could somehow merge my Obsidian vault with mymind’s drop-dead gorgeous UI, its lovely masonry layout and its web clipping capabilities (i.e. presenting social media embeds and other web content as visually appealing cards), I’d be over the moon! Alas, mymind, as it is now, is just a pretty bookmark manager, missing the capabilities of a dedicated note-taking and PKM app like Obsidian.
If I was in the business of software development, I’d take a proper crack at brining my own vision of a second brain to life–just like @silver started Obsidian to “build the perfect note-taking app™”, haha. (Hey, maybe someday! 
)
You may see my feature request for this: