I don’t think there’s an obvious choice, there’s three or four main libs, any of which may be good for different uses.
Some color on confluent-kafka-go - it's a wrapper around librdkafka. librdkafka is the main Kafka C lib and underpins many/most of the non-JVM language bindings. From that angle, if you’re looking for popularity it will surpass sarama. It also tends to have more of the esoteric or long-tail features implemented, though I haven’t done a feature comparison in awhile and it looks like that’s not relevant to you anyways. However it comes with the big caveat/potential pain point of requiring cgo.
segmentio/kafka-go is also worth considering. It’s my main goto if avoiding cgo.