I have built several apps, but I always use MYSQL search queries to build the search features. I have never felt the need to use Elasticsearch. Can someone enlighten me about the use cases where Elasticsearch becomes irreplaceable? Or is it just nice to have?
MySQL's full-text ranking capabilities are quite limited and AFAIK full-text wasn't a priority for them lately. The related article is "Rankings with InnoDB Full-Text Search" [1]
If it works for you - great. If you need more flexibility in terms of data tokenization, matching and ranking you can consider Manticore Search [1] instead of Elasticsearch since it's a continuation (a fork made in 2017) of the Sphinx search engine mentioned in the article on mysql.com and has a better integration with MySQL than Elasticsearch (e.g. you can use Linux mysql client or any programming language mysql connector to make queries to Manticore).
[1] https://dev.mysql.com/blog-archive/rankings-with-innodb-full...
[2] https://github.com/manticoresoftware/manticoresearch