I have yet to find a satsifactory way to disable them - it's pretty easy to disable notifications from userspace apps like Instagram or Snapchat or whatever, but disabling notifications or altogether uninstalling vendor apps is a huge pain in the ass.
Most advice I've gotten has been flash a custom Android kernel or a de-Googled distro. This would definitely solve my problems, but this removes the ability to install Play Store apps which are a necessity for me. Not to mention that it gives the possibility of bricking my phone, which is way outside my risk tolerance for just getting rid of some annoying ads.
In case you do want to install a custom Android distribution (ROM) to clean out the Samsung bloat more thoroughly, the risk of hard-bricking your phone is almost non-existent nowadays. The worst that can happen is usually a soft-brick which can be fixed by reinstalling the original OS. As for Play Store, most custom ROMs either include or support installing Google services and Play Store with full functionality.
Worth noting that Samsung doesn't allow the bootloader to be unlocked in most (if not all) of its flagship devices released in the US. Although, there's paid services that could unlock the bootloader.
It doesn't remove your ability to install apps from the Play Store. You can use the Aurora Store app to install those apps. For the apps that also require Google Play Services, microG usually suffices.
Most advice I've gotten has been flash a custom Android kernel or a de-Googled distro. This would definitely solve my problems, but this removes the ability to install Play Store apps which are a necessity for me. Not to mention that it gives the possibility of bricking my phone, which is way outside my risk tolerance for just getting rid of some annoying ads.