Comment by crazygringo

It really depends on a lot of factors.

It can definitely be frustration, as you keep re-assessing whether it's really worth switching to SwiftUI, and getting upset that something isn't as easy as it was the previous way, for you. I've definitely started switching to a new library and then ultimately stopped because it was too frustrating. What I thought was going to be a better library for me, wasn't. Other times I've learned a new library and felt mostly delight, as I'd discover it was set up in ways that solved all my old problems, and I could see how much time it was going to save me in the future.

Also, you can feel frustration on a daily scale, without feeling frustrated on a larger scale. E.g. you know you want to learn SwiftUI, but today you're running into roadblocks with it, and you need to figure out whether to step back from it today and come back to it tomorrow, refreshed and having slept on it.

If there's anything frustration can be confused with, it's often resentment. E.g. when switching to SwiftUI doesn't actually help you achieve any goals of your own in any direct way, and you feel like Apple is creating busywork with some arbitrary deprecation or migration.

Often, you may feel both -- resentful that Apple is forcing you to learn something new, and frustration that learning the new technology is harder than you'd expected, or not providing the expected benefits, and therefore possibly not worth it at all, or at least not worth it today.