The results are in. VGChartz currently estimates the Switch sold 15.900m units in 2023. My prediction of 15m-16.4m was correct.
@Kakadu18 and @Slownenberg both predicted 16m, so out by only 0.1m.
Ignoring the top two and bottom two poll options to weed out trolls and joke responses the average prediction from the polled users would be 17.5m so Switch sold 9% less than the polled users expectations.