>yes the tip is called the chisel, not the web
It's only a chisel point if the drill has no web thinning or split point.
>The sole reason for a pilot hole is to engage the work piece with the beginning of your cutting edges, instead of the chisel.
>It helps keep the drill from walking, thats it.
Not sure if this is what you meant, but, no that isn't the only purpose of a pilot hole. They're mostly secondary effects, ackshually. The drill is guided by its own flutes, once they're buried in material. Pilot holes are used to keep material out of the are swept by the web/point of the drill. On regular, chisel-point drills, there's no cutting edge at the center of the drill, because it's taken up by the core of the drill. On smaller drills, this basically just bulldozes material out of the way, and, in practice, usually just means you need more feed pressure to make your hole.
But, once you get into larger drills, say, 3/4" or so, the area swept by the web becomes so large that it simply won't remove material anymore. It's like trying to press a nail through solid steel, and it's just not going to happen. Using a pilot hole approximately the diameter of the web (slightly large is best, on-size or very slightly smaller is also fine) eliminates that issue by simply removing that material beforehand. This is also why you can drill much larger holes without predrilling with web-thinned or split-point drills, and why such drills in smaller sizes are so much easier to feed by hand.
>If you incrementally drill holes going up in sizes, its really bad on tool life and hole accuracy.
It's not actually that bad. Most of the risk is from the variable rake between the inner and outer edges of the tooth. It's much higher on the outside, and will either require almost no pressure to feed, or actually try and self-feed in some cases. This leads to a tendency to feed way too fast, making the tooth take an excessive chip and either wear very quickly or just break/chip.