I don’t use dictation often, but I’ve not had any issues on iOS 16 (US English, iPhone 12).
One caveat is that I’d been using the betas, so I didn’t upgrade straight from iOS 15 to 16.0 as released, but I really haven’t encountered any difficulties with dictation in any of the betas or in the final release.
One caveat is that I’d been using the betas, so I didn’t upgrade straight from iOS 15 to 16.0 as released, but I really haven’t encountered any difficulties with dictation in any of the betas or in the final release.