ElasticSearch storage -EBS gp2 or gp3

What is more suitable for elasticsearch storage aws ebs gp2 or gp3?

Gp3 is a good default choice. There were reports of noticeably increased latency around the time it shipped, however since then there have been reports that this is no longer the case: https://twitter.com/jt7d/status/1484310714701389831

Gp3 is also more performant and cheaper than gp2. Personally I would opt for that.

Yeah gp3 unless you have special use case, just for the fact you can finetune after provisioning should you need extra bandwidth etc.