Personally, I feel the the advantage of using the sdk vs experience builder is the ability to customize the design. In 5.0 it feels like way too much of that is being taken away.
Yes. Exactly this. I have been saying this for some time. I began with a 4.17 custom application (my first exposure to the Esri JS SDK). I failed to keep pace until about 4.29. By that point, CSS was still friendly to work with. After upgrading to 4.29, I made a commitment to always upgrade when a new release came out. But around 4.31 or so, my designs started to "break". I was spending countless hours looking at the console, trying to figure out how we're NOW supposed to style things. That worked for a little... until 4.34. At that point, so much of my CSS "broke" (most especially in the popup component) that I stopped trying to chase things, knowing 5.0 was coming out in February. When it arrived, I had to confront the issue. And it has been very frustrating fighting that Shadow DOM. And yes, I VERY much prefer custom apps vs WebAppBuilder or ExperienceBuilder because I can do what a client requests more easily (not just styling but functionality). Now I have begun to expect that, at some point, we will be forced to use out-of-the-box non-SDK options only. And so all apps will look and perform the same. And that's not ideal.
