Correct, most of traffic stats is missing because bridge is offloaded to switch chip. I’m pretty sure that even if traffic was not offloaded to switch chip (e.g. when all bridge ports were set with hw=no), you still wouldn’t see stats. Reason is that VLAN interface (e.g. vlan100_BRIDGE) is only window to one of VLANs available on bridge_vlany interface (see this thread for more on different bridge personalities) and bridge_vlany interface will only show traffic being sent towards bridge_vlany interface (due to dst MAC address) and broadcas and multicast traffic. So normally VLAN interface will only show traffic between router’s L3 layer and the rest of that VLAN (that’s either traffic being routed via router or traffic directly targeting router, e.g. DHCP or DNS - if router is offering DNS to some VLANs).
When you enable torch, HW offload gets disabled (because then all the traffic has to hit CPU, without it torch can’t do the work.