Can I transfer grayed out music from iPhone to PC?

[u/ang-b]

A couple weeks ago, I upgraded from an iPhone 11 to iPhone 14 pro, and set my phone up by restoring from backup. Unfortunately, it appears that all of my non-purchased downloaded music (e.g. albums that I burned or had digital downloads for) is visible, but not playable, and I get the "this item is not currently available in your country or region" error when I try. Furthermore, it seems like some of my songs didn't even transfer/restore from backup, as I can see that some full albums I had are missing songs. If it helps to know, I don't have an Apple music subscription. I've read a little into how to fix this, and I see that one solution would be to go into iTunes (where the original files are stored), connect to iPhone, and transfer. The problem is that my PC that held my iTunes library and downloads was wiped a couple years ago, and I never got around to restoring it, so my old iPhone 11 was the only device that had my library. I have now wiped that iPhone 11 and passed it on (this was before I realized that my songs didn't transfer), so the only potential device I have holding my library is my new iPhone 14 pro. I tried connecting it to iTunes on my PC (Windows 11 laptop) and viewing the iPhone's music library through there, but it unsurprisingly shows up as empty when I do.

I still have the entire iPhone 11 backup from before I wiped it, so maybe somewhere in there is my music library, but I have no idea if I could access it that way, or if it would matter since restoring from backup didn't work in the first place. Is there any hope at getting my music back, or should I just be happy I can still view the downloads (even if I can't play them), and start using it as a list to reacquiring and downloading my library?