Siri worse than ever July 2023

Probably you mean dictation is getting words wrong.

1. If Siri consistently misunderstands your voice, you can go to Settings > Siri & Search > Siri Voice > Retrain Siri to learn your voice better. Retrain Siri with your voice. Go to Settings > Siri & Search, turn off Listen for “Hey Siri,” then turn on Listen for “Hey Siri” again. To change Siri accessibility settings, see Use accessibility features with Siri on iPhone. Change Siri settings on iPhone - Apple Support (IN)
2. Your accent. Siri is trained on a massive dataset of English speech, but it's not perfect at understanding all accents. If you have a strong accent, Siri may have trouble understanding what you're saying.
3. Try using Siri in a quiet environment to minimize the impact of background noise on speech recognition.
4. Make sure you speak clearly and at a moderate pace. Siri might have difficulty understanding if you mumble or speak too fast.
5. When dictating longer texts, you can use punctuation commands like "period," "comma," or "question mark" to help Siri understand the structure of your sentence better. Go to Settings > General > Keyboard, then turn on Enable Dictation. As you speak to insert text, iPhone automatically inserts punctuation for you. Note: You can turn off automatic punctuation by going to Settings > General > Keyboard, then turning off Auto-Punctuation. Dictate text on iPhone - Apple Support (IN)