If you look at the metrics for onion services traffic [0] and total network traffic [1] you'll see that this report is looking at the roughly 1% of tor traffic that is going to onion services. The overwhelming majority of traffic is to the regular, "clear" internet.

[0] https://metrics.torproject.org/hidserv-rend-relayed-cells.ht... [1] https://metrics.torproject.org/bandwidth-flags.html