Samsung embeds IronSource spyware app on phones across WANA

The "unremovable" part is inaccurate. While you can't completely remove it because it resides on the system partition, you most probably can still disable it with an adb command:

    adb shell pm uninstall --user 0 com.package.name

This command is very powerful as it works for any app, even those that have "disable" greyed out in the settings. I disabled the Galaxy Store on my S9 this way for example.

I had a Samsung phone and did the same with mine. Wrote a small tutorial here(https://harigovind.org/notes/removing-samsung-android-bloatw...). But even then, these apps will pop right back after system updates and those were becoming more frequent. I got rid of it shortly after, nowadays I use Moto where bloatwares are comparatively minimal.