https://ground.news/
I think this will appeal to The Core. It's an aggregator, but below each story it tells what % of right, center and left news outlets carry a given story.
In the sidebar it has a "Blind Spots" feature for stories that are being picked up widely by one side but not the other.
The free version is limited by useful.
The cheapest version is $10/year, but you have to spend $30/year to get an unlimited blindspot feed
I've been seeing them advertise on YT channels I like. Looks like a good way to burst out of a bubble. I hope it catches on.
I tried one left-center-right aggregator in my feed about 18 months ago. It was interesting for a while but I eventually culled it.
Here's another one. I don't think this is the one I used.
AllSides | Balanced news and media bias ratings. Unbiased news doesn't exist.
https://www.allsides.com/unbiased-balanced-news