Number of ElasticSearch shards/indices in the AWS OpenSearch cluster

I have an elasticSearch openSearch AWS cluster with 900 indexes that are being created daily. It also has: 4621 active shards 2397 active primary shards. 3. There are nodes. 750 GB of storage. Each index includes at least 2 shards (some have as much as 5), and it is around 40 MB in size. I’ve heard that having numerous little indices is a bad idea; instead, you should mix daily indices with the monthly index. I’m looking for solutions to the following queries:

What are our thoughts about it?
Active primary shards: What does that mean?
Is having 4621 shards for 900 indices normal?
Does performance depend on the number of indices/shards, or something else?
Does combining these indexes make sense?

Thanks for you post. However this forum is for helping people with FreeRTOS. I recommend posting your question directly in the AWS forums.