Is there a way to optimize dictation on iPhone 11?

First time posting here and would like thoughts on Apple dictation. I found some past posts but curious about current thinking. I use dictation when on the go, mostly for text messages and have an iPhone 11. I've found that Apple's dictation accuracy has gone downhill badly in the last couple of years. I try to speak slowly and clearly, but it puts commas in the wrong places, ends sentences prematurely, writes out correctly what I said and then spontaneously changes it to something inane, and appears to like Old English, i.e. it likes to substitute hast for has. I am legally blind with a little bit of sight left, but going further downhill, so learning more about using Voiceover and non visual techniques on the iPhone. I spend an inordinate amount of time correcting what it says before i send messages off. I have Hey Siri turned off because it kept talking to me when I never prompted it, very creepy. From what I've read you need to turn it on to retrain dictation, is that correct and does it help? Are there known things to do to improve dictation accuracy? I was hoping that future iOS updates would help matters but so far has not. I also don't want to spend money on a newer generation phone unless it truly helps matters. Is there an app that one can use to do accurate dictation instead of using Apple native capabilities? Thanks for any advice concerning this.