In practice, the differences between the syndication formats don't really matter. Today even less than when they were created, as a solution for most of the differences is just a prompt away.
In my humble opinion, JSON feed (https://www.jsonfeed.org/version/1.1/) is the most practical format. By a small margin, but still...
- it's really simple and doesn't use XML
- it doesn't allow stupid things like HTML in titles (which I guarantee >50% of all implementations can't handle correctly)
- JSON Feed allows feeds to have a and a (square!) , which is a very practical thing for readers. You can use the in lists of feeds, and the to present a single feed. Atom has a small square icon and a which is supposed to use a 2:1 aspect ratio. 2:1 is completely useless. No site has a logo in 2:1. It's also useless for most full-name logos, like 'New York Times'. (RSS is, of course, even worse; it doesn't even recommend an aspect ratio, practically guaranteeing that RSS readers can look bad)
You can see that JSON feed has been designed from a feed consumer's point of view: what does an RSS reader need to make a feed look good? While Atom and RSS have been written from an abstract publisher's point of view, making everything possible and allowing maximum flexibility. Especially RSS, which has shown its flexibility in becoming the de facto format for podcasts. And both Atom and RSS are really old, written at a time when it probably wasn't clear how RSS would eventually be used.
In the end, no matter which format a feed uses, users won't notice any difference (as long as publishers are smart enough to use square images!). So any feed is a win, no matter whether RSS, Atom, or JSON feed.