I’ve seen the opposite over time in my projects where approachable concurrency is enabled and default actor isolation is set to MainActor. i.e. a vast reduction in having to use nonisolated and @MainActor.
However, there are items that remain. e.g. with Equatable and anything that relates to that (e.g. Hashable). See: Insight needed for `Equatable` with Default MainActor Isolation which is a thread I started in hopes on getting an answer from Apple.
With all that said, I would double-check all your project’s settings and look out for target-specific settings that may have changed.