Sleeping beauty Bitcoin wallets wake up after 14 years to the tune of $2B

Most interesting to me is that people are worried about a $2B transaction moving the market.

How does that compare to the market depth of actual currencies or commodities? BTC, being objectively worthless, must be much more sensitive to people wanting to sell I'd expect.

How is BTC objectively worthless (I'm guessing you mean "intrinsicly worthlesss"?) as opposed to USD or other major currencies?

The expected discounted value of all bitcoin's future cash flows is zero. This is because the only cash flow that a bitcoin investor can expect from an investment in bitcoins is the revenue from selling the bitcoins in the market... and the market value of something that has no use case and is held for speculative purposes only (i.e. has no intrinsic value) will tend to zero in the long run.

A fiat currency that is issued by the government has no intrinsic value either, but there's one crucial difference compared to a cryptocurrency: in the case of a government-issued fiat currency the central bank will intervene the market, by making use of its prerogative to conduct monetary policy, to ensure price of the currency doesn't drop to zero.

And this has proven successful in many countries such as Zimbabwe, Venezuela, and Argentina

Generally speaking it has been successful, more so than the gold standard. It's true that sometimes states fail, but that's not something a monetary system can prevent from happening, or insure against.