I learned to fly in a Stearman crop duster -— a later training bi-plane (came around in the 30s, I think), so I can appreciate the slow speed.
As an aside, you know that buzz, buzzz, buzz, interupted engine sound you always hear in WWI movies?
That was from the engine being turned off briefly to bring the plane to stall speed -— there was NO THROTTLE.
Probably not true otherwise. The Sopwith camel was a rotary powered airplane. Not certain how many others were in service.