I really like you're idea! In fact, I like it so much that I've been working on something very similar at https://lurk.news. I don't have anything released yet though, congrats on getting yours out there, it works pretty well.

I've got a couple of minor bugs to report. The first (very small) bug is that I couldn't sign up with the email address of "accounts (at) lurk.news" because it says that it's invalid. The second bigger issue is that your YouTube search seems to be down? I tried some niche youtubers at first and then just searched for "mr beast" as a sanity check and it doesn't find him.

Are you using the services official API's to find and display content? For Lurk, I wrote an Electron app that opens up websites in the background and then parses the HTML to query for data, then presents that to the user as a unified feed. I figure with it all happening on each client device it'll be very hard for any given website to block it, and that way I can expose an extensions mechanism so that people can scrape whatever they want to get a unified feed of data.