Calculate all sizes

I feel like I'm living in a parallel universe or have time travelled back to 1985 but I would like to propose a simple, brilliant, obvious, missing feature:

The ability to calculate sizes of multiple Dropbox folders.

So that I can select hundreds of Dropbox folders (in the web version to get a true picture of actual storage) then calculate all sizes, then sort in size order. 

This has been a part of most operating systems for what, 20+ years? But Dropbox doesn't facilitate it. 

A cynic might suggest that it's a deliberate move to avoid customers seeing what is taking up space and choosing to delete, using up less space and therefore spending less money. But surely Dropbox wouldn't treat their customers in such a way...?

I've been a loyal customer - and advocate - for many years in the face of cheaper competitors but this has honestly blown my mind.