A friend sent me a link to this. It's on Github or however that's spelled and I tried my best to find the executable, and finally gave the link to my wife who found the program for me. So, for those of you who are interested and don't want to fiddle with Github, here's a public Dropbox link. I'll leave it up for a week or so.

https://www.dropbox.com/s/p0oq2lpid0zhesj/accessible_youtube_downloader_pro_1.5.exe?dl=1

English isn't the developer's native language, so there are mistakes in wording and spelling, but this program is feature packed.

Can you also provide the GitHub link please? I always prefer downloading from original source.

I'm sorry, I don't have the original link.

I found the link to the GitHub page, hopefully that's ok. If not I'll see whether I can get the direct link, but it is very fiddly indeed.
https://github.com/sulaiman-alqusaimi/accessible_youtube_downloader_pro

It's fine, and thanks, Karl! I followed the instructions that were in an email I got and still couldn't get it. Glad my wife figured it out.

A challenge? I like the sound of that! :)

Well, I'm not sure what problems you had getting the executable, it took me a mere 5 seconds.

I'm really, really, really glad for ya!

This is quite nice

The download speed is rather slow but yeah, a quite nice program.

Glad that the file is still available for download, so thanks!

Oh, you're welcome. I probably should've attached it but I didn't, so I'll leave it up longer.

but... what's can make this program?

Can you reword your question please?

Oh, and I found out that I couldn't attach the file as it's too large, oh well.

This program no longer works, so I've taken it out of Dropbox, thus disabling the link. I suppose Google killed his way of working with YouTube. Very sad, but probably inevitable.

Hmm. Long live pontes media downloader

Or, an NVDA-addon that someone wrote! Here's the link:
https://cloud61.de/index.php/s/TBnTN3T8X2KCQ3m
And here's how it works. Just place yourself in your browser on a YouTube video. Then, you can use NVDA + y to convert to mp3, and NVDA + shift + y to download as mp4. NVDA + control + y opens the folder where the downloaded videos are saved, and that keystroke works from anywhere of course. You can't set the location yet, but if you can open the folder with the above mentioned keystroke, you just move it to where you want to have it. I think that's so cool, since it's just one keystroke! And then just open the folder and move it, but that's it! I used Elten before, and that was good, but this is even better, and then, I wouldn't miss out on that if I ever left elten. Don't worry by the way, even though the website suggests German, the addon is in English.

Oh but of course, if you want to have it in another format, say, wave, then this addon isn't an option.