They are kind of two separate things.
Pi-Hole will work on literally every device on your network. It can block ads on smart TVs, cell phones, etc. It can prevent certain forms of tracking on video doorbells, voice assistants, cameras, etc. You can also set up custom DNS to restore online service to old game consoles or to host web services at home.
You also get all the metrics. For example, I can see that my computer reaches out to my printer several times a minute and that the Oculus app for my Quest 2 was reaching out to its servers even when the app was “closed”.
You could also use it as a sort of parental control. It can provide one set of block lists to the parent’s devices and a different one to the kids devices. Or you could do the same with IoT devices so they are only allowed to reach out to the services they need to be able to run.
uBlock is still important though. It’s possible to get around a DNS filter like Pi-Hole by serving ads from the same domain that the core service is served through. uBlock Origin can do things like block YouTube ads for instance.
