> Both of those have steep learning curve, but it's hardly because it's a mess or it's old.

Bitpacking structures used to be important in the 60s. That time has passed, unless you're dealing with LoRa, NFC or other cases of highly constrained bandwidth there are way better options to serialize and deserialize information. It's time to move on, and the complexity of all the legacy garbage in crypto has been the case of many a security vulnerability in the past.

As for the code, it might be personal preference but I'd love to have at least some comments referring back to a specification or original research paper in the code.

I think you misunderstand the problem asn.1 solves and constrains it works within (both 30 years ago and now). We sure can have a better one now once we learned all the lessons and know what good parts to keep, but this critique of bitpacking is misplaced.

ASN.1 is not used because of just bitpacking. There are other benefits to ASN.1 and it's probably one of the least problematic parts there.

People who have thought they can do better have made things like PGP. It's one of the worst cryptographic solutions out there. You're free to try as well though.