Very, very few people need root access and the ability to see all raw data. For example, at Google, this is a tiny number of senior SREs and that's it. Your average employees should be using audited UIs running through service accounts that have restricted permissions.
The solution we had wasn’t particularly difficult to set up, and actually made life much easier for everybody, because we’d provided everybody with a very easy to use interface for the data they wanted (much better than the old school shelling into a DB to run your arbitrary SQL statements).
Everything in the data warehouse was anonymized, and people only had access to the schemas they needed (though this was defined quite broadly). Anonymization was handled by our ETL pipeline. When we first set it up, the requirements were pretty simple and we just wrote a little java app to do it. This scaled pretty poorly, and the team ended up putting a proper ETL product in there. I can’t remember which one they used, but there’s a lot of perfectly decent products in that space (even some open source).
Agreed, data governance is important for any company to get right, but someone has to have DB access in order to manage it. When you factor in that so many companies derive revenue from the data they generate, then it gets harder.
If you’re Twitter, how can you build the services you need as an architect or data scientist without the actual data?