No app is completely uninstallable. But the one app in Iodé that can’t at least be uninstalled via system settings is the Iodé tracking protection.
Iodé is considered one of the more secure custom ROMs and friends of mine and me are quite happy with it (running on a Terracube 2e, a Fairphone 3, and a Fairphone 4).
I loved Pretty Good Music Player and am since then looking for a good FOSS folder based player. For now I’m using Foldplay.