Except when the government starts then mandating a specific algorithm.

And yes. This has happened. There’s a reason there’s only the NIST P Curves in the WebPKI world.

"The government" already have. That's what CNSA 2.0 means - this is the commercial crypto NSA recommend for the US Government and what will be in FIPS/CAVP/CMVP. ML-KEM-only for most key exchange.

In this context, it is largely irrelevant whether the IETF chooses or not to have a single-standard draft. There's a code point from IANA to do this in TLS already and it will happen for US Government systems.

I'd also add that personally I consider NIST P-Curves to be absolutely fine crypto. Complete formula exist, so it's possible to have failure-free ops, although point-on-curve needs to be checked. They don't come with the small-order subgroup problem of any Montgomery curve. ECDSA isn't great alone, the hedged variants from RFC 6979 and later drafts should be used.

Since ML-KEM is key exchange, X25519 is very widely used in TLS unless you need to turn it off for FIPS. For the certificate side, the actual WebPKI, I'm going to say RSA wins out (still) (I think).