Yes, importing a feed list from OPML is no problem - and it’s something you could do a decade ago with apps like NetNewsWire. But the main advantage of a feed service is that it polls all your sites (I have 1423 right now) for you and they’re available immediately on the website and within seconds on a reader app. Also, services like NewsBlur, which I use, offer full-text search, they can show you popular sites, popular saved pages, let you tag, let you create saved searches. NewsBlur lets you ‘train’ feeds to flag based on site, type of post, author, and blog tag. You can also create a mini blog in which you can privately share feed stories with others via link. NewsBlur is also free for up to 64 sites, and is one of the cheapest services unlocked, for $36/yr. Services like this offer so much more than having to manually pull up individual feeds by themselves.