You can download a DRM-free copy of any audio track you bought in the iTunes Store. It's been like that for around 10 years.

>Buy music from Bandcamp and save it on your hard drive. That is yours

but itunes music is DRM-free as well?

You would only lose access to music not saved in an accessible location (and purchased after DRM was removed unless you took the steps to get drm free tracks[1]) and also software bought on the App Store.

[1]funny story: I have one (or more) tracks in my music library that a friend shared with me almost 20 years ago when we were in college and he added me as one of the 5 computers that could play the tracks. Every time I’ve moved my library to a new computer it asks me to log into that account to approve that track, but it won’t give me a list of the tracks so I can delete it/them. It isn’t enough of an annoyance that I’ve tried too hard to find them.

Are you sure? Legally speaking you might be required to delete it then.

https://xkcd.com/488/