Sequelize is extremely simpler and writing code with it is a joy compared to hibernate.
When you say nobody uses different database that’s true 99% of the time but i worked with a company which developed a tool that must be placed within customer infrastructure and this type of customers force you for the db choice since they have highly paid db support teams (financial sector) so they had to support multiple dbs.
A year ago i had to develop a big Java application without orm (cto’s choice): i didn’t remember how tedious, error prone and slow is development without orm!!! Never do it again!
I think the best approach is to use orm for common crud tasks and add specific sql queries when things get a little bit complicated.