I think the chubbyemu video had the best summary where it simply says do not eat instead of something like contacting poison control or a more serious warning.
Another amusing thing is the old Jeff foxworthy line: you know why it says Do Not Eat? Because someone ate it. Imagine buying a camcorder, seeing a little pouch of marbles and thinking 'im gonna eat this'
NGL, I have almost eaten a lot of desicant packets because they have them in a lot of beef jerky packages. Jerky is one of my favorite road trip snacks, so I'll be blindly grabbing jerky out of the bag either while driving, or possibly in a dark passenger seat because I tend to do a lot of driving at night or early morning to avoid traffic, so I'm blindly shoveling dehydrated meat into my mouth, and soonermor later that little packet tends to find its way to my mouth.
I had a patient once who had a med that is dispensed as these giant tablets with one of those plastic cylinder style silica desiccant thingies in the bottle. One day he swallowed the cylinder instead of a tablet and didn't even realize it. Ended up in the ED a few days later with a badly bleeding stomach ulcer from where the silica cylinder had adhered itself to the side of his stomach because it was desiccating the mucous membrane there.
So choking isn't the only hazard. Probably just more common.
Here's a fun one: silica gel is also used as a pesticide by exterminators. Say you have an infestation of wasps in your roof and they're getting inside the house. The exterminator will fire a blast of dried silica powder into an open point in the roof, and the silica dries out the nest of wasps. They become instant mummies.
Another fun fact: You can use it yourself. Just spread it on the floor where you have a bug infestation and it'll kill them. It's harmless if you don't ingest it (in fact, I believe there's even some that's food grade).
If you have bedbugs, you can surround your bed with it, and it's really effective. It also takes out cockroaches, I believe.
Anhydrous silica should absorb at most, like, 50% of its weight in water. It is not enough to dehydrate your insides, I bet that even the same amount of salt would be a bigger issue. And for most part it would be like eating sand, not exactly pleasing but not life-threatening either.