While the K3 isn't QUITE dead - why would you want it? It has all the frustrating parts of the K1 (adjustment of status) and none of the benefits of the spouse visa.
In the past few years, K3 issuances have been as follows:
2018 - 5 K3s issued (Mexico - 2, Bahamas, Brazil, Honduras - 1 each)
2019 - 7 K3s issued(Mexico - 3, Afghanistan, El Salvador, Venezuela and Yemen - 1 each)
2020 - 2 K3s issued (Honduras and Yemen)
2021 - 2 K3s issued (Mexico and Pakistan)
2022 - 4 K3s issued (Mexico - 2, Great Britain and Brazil - 1 each)
2023 - 6 K3s issued (Democratic Republic of the Congo - 2, China, Great Britain, Morocco and Yemen - 1 each)
The only one I know the full detail of was the one from Morocco in August 2023 - basically because they were asking questions on a FB group and I didn't believe their K3 had been approved by USCIS so I asked and they sent me pictures and I kept thinking that they wouldn't actually GET the K3, but they did. In their situation, the couple had filed a K1, then got married and (unknowing the proper steps) filled out the I-130 and a couple days after the I-130 was filed they K1 was approved so they sent a request that, since they were not married and had filed the I-130, that the K1 be changed to a K3 - and surprisingly it was - which they verified through all NOAs and visa issued to me.
I'm pretty sure they got lucky and it was a fluke. For the others that have been approved - I always wondered if they MEANT to get the K3 or if theirs were by accident also.