RDRAND has a throughput of hundreds of megabytes per second on most processors. Getting 226 bits is pretty easy, even shuffling millions of decks per second you'd be bottlenecked elsewhere.

(That does sound like a fun optimization challenge: "write a program to fairly shuffle the most decks of cards per second possible.")

Depends on what you mean by "truly random" but if it's "cryptographically secure random" then it's not particularly hard.

There are strong monetary incentives to break all kinds of private keys but most of the time they hold pretty well.

Quantum random number generators are commercially available, relatively inexpensive and can supply hundreds of megabits per second of truly random data from a single PCIe card.