Advantages of using shrink API

Elastic Stack Elasticsearch
1

Hello. I was looking into Shrink API and in what cases it can be used, and I found three main reasons to use shrinking:

  1. Resource economy
  2. Faster search
  3. Big shards are more suited for long-term data storage

However, I don't really understand how having a small number of shards relates to those. Also, are there more reasons to use shrink API other than those?

2

If you have only one shard to search on, it will make your search faster as you don't have to hit multiple shards and merge the results.
If you have then one single segment in this shard, that could be even better.