I like that it's very simple to make a page with links in every direction without having to write any code at all! It also has some cool features such as being able to use images instead of text in your content blocks (which makes sense!).
The only thing about linkcards I don't care for are how they're presented when you first open them up - there should be an option to change this so we can see what our visitors will actually view once their on our pages. We've been using link cards to create landing pages for multiple clients over the last year or two. They have proven extremely useful because it takes less time than other options out there and allows us to do things that would otherwise require coding (like adding social media buttons).