Really, not kidding. There seems to be no real standard for footwear to utilize while excavating. Certain conditions require fairly specific shoes, such as very wet sites where either rubber boots or no shoes at all are required. Indeed, I recall reading that at certain cave sites (or maybe just one) in France, workers are not allowed on the excavation surface at all, but do all their trowelling from boards suspended above the ground. Obviously the problem that one faces is that one is stepping on the very material one is trying to excavate, and that this can cause damage to the artifacts one is trying to recover. My first excavation was in a shell midden where this problem was especially acute given the methodological aims of the research, one of which was to determine the average size of shells within different strata. Needless to say, stepping all over fragile shells will crush, and therefore diminish in size, the uppermost surface shells.
In part, this is mitigated by the protective properties of the ground itself. You're only really stepping on the surface material, while the artifacts a couple of centimeters down are still safe in their coccoon of sediment.
Nevertheless, it's probably something to think about. Heavy boots with knobby soles presumably do much more damage than a softer, flatter sole. Hence, the idea that the above Chucky D's might represent a good all-purpose excavation shoe, which was originally suggested to me by a senior colleague many years ago. They have a fairly flat sole (especially after having been worn for a while), the sole itself is not very thick or rigid so it conforms to one's foot a bit more, and they're high-tops so there's some protection from both dirt and creepy crawlies sneaking in while you're working. Technically, an ideal might be something like a sock with a strong but soft fabric sole but this seems to be pretty close to that already.