Since 2000, I occasionally used Dragon Naturally Speaking, the original dictation software. While Dragon became 99% accurate, and is still available, it's probably been largely superseded by other applications such as built-in dictation in Windows and both Android and iPhone smartphones.
Dragon was designed to transcribe-as-you-watch, so it was designed to convert punctuation words into symbols (comma, period, new paragraph) and provided real time editing (scratch that = erase last word). So using Dragon was a pretty manual process. The last time I tried it with an mp3 file, the results were quite bad.
Windows has built in dictation software now, with the advantage that, like Dragon, it will work inside a program like a Word document or an email window. I think it's pretty darn good but I don't use it much.
Auto Transcription in the Cloud
If you go outside Windows free software, one of the best choices is Otter.AI. Otter has a basic service for three (I think it's 3 files per month) and it seems designed for uploading MP3 files and then transcribing them over a few minutes. It's quite accurate and attempts to completely supply punctation (including commas) and paragraphing. It also segregates voices, which is pretty accurate (Speaker 1, Speaker 2, Speaker 3). If you identify voices (Speaker 1 in one document equals Bruce) it will find and label that speech pattern in any future transcripts.
Sometimes, Otter.AI is too choppy. You might get a timestamp 4:31 min/sec and a few words, and then another time stamp 4:35 min/sec and a few more words, rather than a coherent paragraph by one speaker.
Otter vs Siri
What's interesting is the comparison between Otter.AI and iPhone Siri dictation. In my experience, Siri works great for variable 10 to 30 words, and then freezes, stops. On the other hand, Otter.AI is designed to chug along even with a 4 hour mp3 file. So you can dictate paragraphs and paragraphs into Otter.AI and it will keep up with you. So if you want to dictate for 15 minutes, I can't get beyond 30 sec in Siri but I can do that in Otter.
One difference is that iPhone Siri is set up as "dictation" software - recognizing words like period, comma, paragraph - while Otter.AI is auto-transcribe software from a voice track, so it will type "comma" for the word comma and it will insert punctuation solely where it thinks it should, automatically.
Otter - Not free, but real cheap
I mentioned Otter.AI has a limited free service (a few files a month). You get a huge amount of time (I think it's 100 or 500 hours) for a nominal monthly charge (like $9.99), so if you buy into Otter at all, you can upload mp3s to your heart's content or dictate (into Windows or into an iPhone otter app) to your hearts content. All the dictations show in a consolidated list of documents in your Otter account.
Bells and Whistles
Otter has a function called auto transcript in ZOOM which I believe is an extra fee. All the participants on a Zoom call can then see a track of the transcription in real time.
A relatively inexpensive human transcription service is is REV.com. This is $1.20 per minute or $72 an hour for a highly accurate human-curated transcript. (REV will also do only an autotranscript for $0.20 per minute or $12 an hour, which is pretty high for an auto transcript). REV will accept link files like link-to-youtube as input, Otter will not. For example, to get an auto transcript at Otter of a Youtube file you would need to record it and then upload as an MP3.
Take Home Lesson
Sometimes I used to use Dragon to dictate notes while reading, or dictate notes from a page of handwritten meeting notes. I can get back to doing that with Otter, whether I am doing it online in Windows on my Otter webpage account, or whether via a matching phone app on the same account.