Okay, I think you're talking about startups using Google sheets as a database?
I don't see data security as an issue, because it's access is restricted to company emails only.
Making sure it's correct, is a process problem and not a tool problem. If you're spending too much time checking if the data is right, ensure there is a proper analytics and data engineering team which creates and maintains data properly.
Finances have traditionally used excel/sheets in combination with their accounting software's, they know it gets the job done.
Google sheet becomes a problem when there are manual interventions to data and not systematic, then it starts to get fucked.
I've personally seen both sides of it, at a startup where it was fucked and at a place where it's used incredibly well.