Transfer music playlist between platforms
Tune my music: https://www.tunemymusic.com/
This tool allows you to transfer playlists between platforms like Spotify and YouTube Music, or export your playlist to a CSV file.
If you want to move all tracks from one platform to another without worrying about individual playlists, you can consolidate all tracks into a single list. Both Spotify and YouTube Music allow you to add one playlist to another while skipping duplicates, so it can be relatively easy (depending on how many playlists you have) to merge everything into one playlist for a single transfer to the other platform.
Please note that "Tune My Music" has a limit of 500 songs per transfer in the free version, so you may need to split a large list into smaller parts.
Also, you'll need to share the playlist on the source platform and grant access on the receiving platform, but you can revoke access afterward.