Pulsar is far better designed than Kafka and is much more reliable and scalable. Clients in every language are an entirely different issue and mostly down to developer bandwidth because it's a small team.

Kafka actually doesn't have that many great clients either, they all are just wrappers around the C++ librdkafka library.

Pulsar clients are also easy to create because of the stateless protocol, per-message acknowledgements, and optional websockets API. Or you can just use their Kafka bridge adapter and use your existing Kafka clients.