Mine is Local Send which is a FOSS alternative similar to air drop that works across a variety of devices.
Warning, I might be wrong:
yt-dlp seems to be operated with command lines, whereas cobalt is a user interface in an opened browser tab. You paste the link of the desired video or audio source into a search bar and you can toggle different settings (bitrate, file format, video output size etc.). The desired file will be appearing as a download into your download folder.
Ooh nice - if it is indeed a UI it would be perfect for my grand-aunt. We went through many such alternatives, but all stopped working after a while