Not unless your application aims to encompass the entirety of running a business. Otherwise it's just plain user-hostile greed.

Personally, I do love whenever applications allow to export data and lack of such feature is IMO strong negative.

It's also much more efficient for me as a developer to offer an export interface instead of having to implement all the reporting functionality myself.

You are right I don't want to be user-hostile greedy. Its a fine line.

You can't stop it. If you don't have export then you will hear about your clients copying and pasting to Excel. Much better to add a csv export and high-res download button for all charts and graphs.

By the way, I've had lots of success with chart downloading by simply copying the svg element into a request to an svg to png converter.

Often it already is. Export from here, import to there. SaaS is more and more common, so the glue needs to get better.