Personnaly I use ETL tools at work. However, most of large industries settle on using coders to do the integration and transformation ? Isn't it easier and time efficient to use tools and dynamically manage the data flow than having to write codes in terms of cost vs time chart?
it’s like an intellectual superiority contest.
at certain levels of scale ETL just doesn’t work effectively though, so maybe good to start ETL then once you out grow move pieces to custom coding