Technically I agree with both statements. SwiftUI is still in a bad shape for anything that requires performance and fine tuning. Navigation, especially something not standard - forget.

When it comes to swift concurrency - I personally did not find anything wrong with it. Just it seems so simple, that even in the easy code you can make a huge mistake. It is also easy to forget that it saves the entire context while executing and it may lead to memory leaks easily. And it were supposed to be designed to protect you from such mistakes. Instead it is easier to make them than when you are using CGD. I think a great talk about problems in Swift Concurrency https://www.youtube.com/watch?v=HqjqwW12wpw