Still. I have had MySQL corrupt tables with way less load and data (in the less than 10GB size range)
The company here is doing petabytes of data and millions of ops per second. That’s scale.
We should be clear about what “at scale” means, and 6.2TB is not.
If table corruption is acceptable, you might as well just serve data from /dev/urandom and store user data to /dev/null.
How many Uber rides are happening every second? I suppose it depends exactly on their setup, but I could see that being at least the right order of magnitude.
EDIT: According to the Internet, there are about a billion Uber rides per year, which makes for about 31 rides per second. Even if there are 1000 transactions per ride, 21k/second sounds approximately Uber scale to me.