I used to use my SD card for music, on my S10. I collect live performances of various artists so used to keep separate SD cards for different bands so I could swap them over easily. I miss this with the s21 as it is really inconvenient.
Progress is a pain, some times. I know SD cards are unreliable and cheaper memory is making them obsolete but I miss mine.
Totally agree I still keep my old S10+ as a backup and music I have Spotify so I save the data on the sdcard. With my S10+ have all the editing apps and social media etc. S21 I keep minimal by basic apps WhatsApp and Instagram