Obsession and addiction are the same thing, experienced by different aspects of one's being. Obsession occurs when the mind is trapped in orbit around a particular object, behavior or interest. Addiction is the same stuckness, manifesting physically. One is hardly superior to the other: if you can't play your best competitive tennis without your special rituals, clothing and equipment, you're addicted no less than the person whose body has been invaded by need for a particular tickle: coke, 'drines, sex, alcohol, pot, etc., and will do whatever is necessary to obtain it.
Either one diminishes the rest of the world.
Almost 400 pages into IJ, I've found a character who seems "normal", though that is a consequence of damage: Schacht is an "under-18" tennis player whose ranking is on the wane thanks to the one-two punch of Crohn's disease and a permanently injured knee. He can still play, but not at the champion level. Unlike his classmates who oscillate between obsessives' poles of tennis and recreational drugs, he accepts his lot. He's studying to become a dentist, and his game has reached a Zen zone with a high achievement-for-effort ratio because winning no longer matters. Likewise he can take or leave the drugs. He is free, and so far he's the only character I can think of able to make such a claim.
As for waste: as we learn the history of O.N.A.N. (Organization of North American Nations, which excludes the Concavity where separatist Quebec seethes), we begin to grasp that the consumption on which our economy has been built since the end of WWII has generated a waste stream so massive that we've run out of places to dump it. It appears that the waste zone for toxic North American residue is The Concavity, and from the Boston area, near its border, regular launches by the E.W.D. (Empire Waste Disposal) are shot skyward - though probably not into orbit (I haven't got there yet).
An obsessively notated book offering obsessive amounts of detail about its topics seems a natural spawning-ground for obsessives, and all you have to do is Google Infinite Jest to see that they are legion. DFW's end-notes expand in likewise obsessive fashion on the subject of mention, whether that is a game of chicken played by young men in Quebec, or the filmography of the Incandenza family patriarch, or a phone conversation between brothers which reveals a great deal about certain events in that family. You can no more skip the end-notes than you could skip dozens of pages in the body of the novel - they are part of the story. Whether much of the information offered in the almost 100 pages of end notes belongs there (as opposed to nested in the narrative), is a moot question. There it is, and there you'd better read it.
Still, he has a way with words. How can any writer fail to love a sentence like this:
[Schacht is] one of those people who don't need much, much less much more. ?There are some very funny moments (which I won't relate here, since that would both pull them out of context and spoil the surprise of coming upon them) - not infinite, perhaps, but some good laughs. It has taken awhile, but somewhere between a quarter of the way in and a third, I have identified the outlines of a story I want to follow. What happens to these people? What happens to these nations? I'm sure those answers lie ahead.