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.
There are a few competitors: Google Titan, Thetis come to mind plus traditional smartcards. Some of the competitors only support FIDO/U2F, meaning that a number of applications like LastPass that support OTP or Smartcard won't work (if you're interested Yubikey's Security Key only supports those two protocols and only costs $20). Yubikey's build quality tends to be superior and they've got a nice plug and play UX. For many IT departments, it's easy to justify an extra $5-$10 a unit if there is minimal support needed and it's unlikely to need to be replaced due to breakage (lost devices yes, breakage no). Anecdotally I've got an older generation yubikey that appears to still work after 6-7 years
And usually it's twice what they charge, because you need a backup device to handle losing the first one.
I'd like to see a competitor come out with a combo PIV card & FIDO device. At least from the enterprise perspective it would cover 99.9% of MFA situations. And the majority of my personal uses of YubiKeys.
It is probably more pricing of different products in their selection. If you just need U2F you can get their security keys [0] for 20$. 18$ if you order 50, and probably even cheaper if you ask for > 1000 (i.e. an entreprise customer).
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.
I suspect YubiKey doesn't face price competition from the cheap AliExpress USB flash drive manufacturers because a U2F token from a no-name supplier isn't much better than a mobile app.