[Avamander]

Because it has a shitton of issues. The implementations aren't great, cryptographic issues, memory safety issues, stable API/ABI issues. It's still not supported well by software that could use these features.

[GekkePrutser]

Most of the security issues are mitigated by using a hardware token to do the actual encryption anyway.

[Avamander]

Those are expensive

[georgyo]

You do realize that the solokey is a hardware token....

[Avamander]

Yes, but a Solokey is half the price of a Yubikey that could do the encryption implied by OP. And to be fair, even Solokey is too expensive for most.