A tip you might want to consider if the storage on phones becomes a non-issue for you: ditch the standalone MP3 player with the nice DAC, and just get a high-quality Bluetooth DAC like the Fiio BTR3 (which honestly sounds just as good as my home stereo) that you can pair with your phone.

I used a standalone MP3 player for years in addition to my phone, because I couldn’t find a phone with a decent DAC, but now the existence of Bluetooth DACs means I have less to lug around.