How do you limit phone/internet, and still use them for work/utility? I have some tricks, but still find this to be remarkably tricky.

So many things are useful/necessary, but are tightly bound to the addictive crap.

For instance, for buying/selling used items in my area, you really need to be on Facebook marketplace. But on Facebook marketplace, all the rest of the Facebook addictive stew is staring you in the face.