I had the same challenge when working with MongoDB in Scala 3, as the official MongoDB Scala Driver currently only supports Scala 2.x.
To bridge this gap, I developed MongoScala3Codec, a Scala 3-compatible BSON codec generator, inspired by the macro codec in the MongoDB Scala 2 driver. It enables seamless serialization/deserialization of case classes in Scala 3 using macros.
You can check it out here: GitHub - MongoScala3Codec.
As for an official MongoDB driver for Scala 3, I haven’t seen an official timeline yet, but I’d love to see an update from the MongoDB team on their plans!