If you don’t have growth you have to treat this as a PE firm would. You cut spending to a minimum while ensuring you keep your customers, thus maximizing profit to assets ratio. A lot of companies do not have growth but are great money machines. It may be that this is the mature stage for Dropbox.
(Dropbox customer, pls just sync and store my data reliably)
Edit: Reply was as I expected, thanks bhouston, agree they are potentially at the mature stage