It hasn't improved much since its introduction with Mac OS Mavericks 10.9.5. How horrendously pathetic and Apple should be thoroughly embarrassed over their lack of dictation improvements over the years. I hope these suggestions will help your situation. I wish Apple would get busy improving their dictation software and include older Mac OS versions but I know that's never going to happen. I see that some places still sell Dragon Dictate for the Mac, but I sure didn't feel like spending $300 usd for a discontinued and unsupported software.

One has to search out that feature to get that price. I also have added Voice In Voice Plus which provides some additional features that I believe cost $25 us for Lifetime use and upgrades. Short of a fudge workaround but it does work and certainly can save one's hands and any other injured body parts, and is certainly more accurate than Apple's dictation. The Google Chrome extension that works very well for me is Voice in Voice Typing, but I also use its Developer's Dictanote software Dictanote - Make your voice type for you which you can use with a browser to type into and then copy and paste into any application. What I have found that works quite well for good accurate dictation are some extensions and applications but they only work in Google Chrome type software. I prefer to use Mavericks, 10.9.5 which has the original Mac OS dictation which has a lot to be desired, and I haven't noticed any huge Improvement in later macOS versions when I have had a chance to use it. I am in a similar situation to you as a result of psoriasis rheumatic arthritis and gout in my hands and Dragon Dictate for the Mac went kaput when my condition became serious, so I don't even have it to use.

Dragon dictation for macbook pro