These are also easy to DIY with a raspberry pi, rfid card reader, some blank cards, and phoniebox [0] for the software. I don't have much electronics experience and had it up and running fairly easily for under $40.
I expect there are big benefits to portability, but I'm okay with not having them.
Is there anything else I'm missing?
I had a listen to Yoto Daily, and it's nice! https://feeds.acast.com/public/shows/yotodaily
The relaxing music plays the same track, or varies it? I guess it's on for ~20 mins or so?