One thing I'd love to see with rss / ompl sharing sites is more ease of exploration. It feels a bit clunky browsing many of these feed sharing sites because you need to evaluate each feed by manually clicking through each one etc or worse you can only import the whole opml at once flooding your feeds. For example I've seen some sites with feeds directly showing posts as they come in for each persons feed list(s) so you can see what that batch of rss feeds looks like in action without clicking around much. There are some sites doing great work getting people to share their lists but I think there is room for qol improvements.
One site I've been liking that has feeds for each list and is trying to reduce friction on sharing is blogflock.com. You can also follow other peoples lists directly on the site too so they show up in your main feed. I believe I've also seen some people self host their blogroll on their personal sites with similar feeds but I'm having trouble finding that software atm.