I started generating the JSON version in 2011.
http://scripting.com/stories/2011/03/17/jsonifiedRss.html
It took a few minutes to write the JSON rendering code, that’s how close the two serialization formats are, so if you want JSON, you can have it.
[1] https://opml.org/blogroll.opml
[2] https://alexsci.com/rss-blogroll-network/discover/feed-c550c...
You can also see one in action on my blog's home page.
http://scripting.com/
And on a special site..
https://blogroll.social/
A blogroll is a kind of feed reader.