Why is there so little competition for these? $50 for a key that maybe costs $5 to manufacture (yes, including software development, at their volume) is a little too rich for my blood.
And usually it's twice what they charge, because you need a backup device to handle losing the first one.
I'd like to see a competitor come out with a combo PIV card & FIDO device. At least from the enterprise perspective it would cover 99.9% of MFA situations. And the majority of my personal uses of YubiKeys.
It is a fairly niche (although growing) market, and you also don't want to buy the cheapest product in the space as it might not work securely.
And 5$ manufacturing for 20$ resale is pretty much a standard ratio in consumer goods. I would also argue that a competitor would have a hard time making those at only 5$, making it harder to compete based on price alone.