I've done a bit of experimentation with Wisper.ai alongside Subtitle edit.
When you run the program you can choose from five sizes of program, "tiny", "base", "small", "medium" and "large".
The larger the file you choose, the longer it takes to transcribe, and the more accurate it is.
I found that when I made subtitles for part 1 of my miniseries, which is just under an hour long, the tiny file wrote the program very quickly, but was way off. When I used the large file, while the result was much better, it still was far from perfect and I had to go through the whole thing to make corrections. Which is a lot quicker and easier than making subtitles from nothing, but it isn't at all a one click and done affair.
Overall, most lines were transcribed correctly, but the timing was off, and the sound effects were almost entirely wrong.
The AI makes an admirable effort to figure out who's making what sounds and what their names are, but as you can imagine, that's a nigh impossible feat. And the first thing I did was go through the file to delete all instances of "(wind blowing)".
All in all, I was able to complete the subtitles in a single day, while multitasking, but the time taken for the subtitles to auto-generate seems to grow exponentially with the video length.
When I tried making a file for the full series, which comes in at just over nine hours, I found that the large file took impractically long. I found that the largest program worth using on a video of that length was "small" which turned out to be a "set it going before bed and come back after work" kind of deal.
Overall, making subtitles this way actually takes longer from start to finish, but the time you actually have to spend sat at your computer is obviously less, though I'm not sure exactly how much.
The real upside is that it's nicer to edit a file than to work from scratch (and, let's face it, this is a fanedit forum, nobody here likes working from scratch).
This will probably be the main way I create subtitles for my edits, but if someone said they preferred going totally manual I wouldn't be surprised.