Progress is being made on replacing OpenSSL in a lot of contexts (specifically, the RustCrypto[1] folks are doing excellent work and so is cryptography[2]), but there are still plenty of areas where OpenSSL is needed to compose the mostly algebraic cryptography with the right wire format.
Edit: I forgot to mention rustls[3], which uses ring[4] under the hood.
[1]: https://github.com/RustCrypto
[2]: https://github.com/pyca/cryptography
TLS 1.3 specifies which curves and ciphers: https://en.wikipedia.org/wiki/Transport_Layer_Security#TLS_1...
(IDK what the TLS (and FIPS) PQ Algo versioning plans are: 1.4, 2.0?)
Mozilla [Open]SSL Config generator: https://ssl-config.mozilla.org/