It would be very difficult to track the following:
Total number of bricks planted on servers. (In theory, you could track how many times you attempted to plant and got no error, however, an error isn't shown for everything, such as needing a baseplate or not having enough plastic in DRPG)
Total number of bricks destroyed on servers. (Simply impossible to track on the client side)
Total time spent flying. (Flying in a vehicle or just flying in general? Because if it means just as a player, it would be difficult to track whether you're actually flying or not.)
Total amount of jumps. (It's easy to determine if you attempted to jump, but no way to tell how many times you bounced while holding space or if you even jumped when you pressed space)
Total number of kills done on servers. (Many upon many of add-ons like to screw around with how messages are sent to the client, such as using untagged messageClient commands.)