Before making any such comparison you first need to establish equivalent conditions in the two cases;   the same standard of helming and crewing,  same crew weights,  the same wind conditions,  the same wave conditions,  etc.

The intention of the Committee in setting design standards and in licensing builders is that in terms of performance there should be absolutely nothing to choose between the two materials.   How well (or otherwise) that works in practice is of course what you are trying to ascertain.

Certainly our strong impression is that at Championship-winning level the honours are evenly divided.

And incidentally it is not always the newest boats which win.   Think Racey’s Rocket (Mike Senior,  the current World Champion,  won in 2018 when the boat was over 20 years old),  and decades earlier Gwladys Too (David Warden-Owen,  UK National Champion in 1970,  when the boat was somewhere around 16 years old);   both seriously old Championship-winning boats,  and incidentally both of them wooden boats.

By far the biggest factors determining the speed of any given boat are the skill levels of helms and crews,  their physical fitness,  and the degree of preparation of the boat.   Whether wood or plastic appears to be irrelevant.

Oliver