It's about the average watch and a forum like the purists where you have several brands and not only Panerai LOL ( does TZ ring a bell ?
Anyway why do you think that Rolex makes bigger sportswatches and bigger datejusts and day-dates, sky-dweller. Even Lange increased their watches, (saxonia, Lange 1 Tourbillon, Zeitwerk, Richard Lange PLM, new Dato, ...
AP's Millinary became bigger and so did the new RO
I see several new Breguet watch above 40 mm, and the same goes for Blancpain
Doe sGreubel Forsey makes a watch smaller than 42 ?
Lang & Heyne, also between 40 and 45 and
Look at the IWC watches made in the past 5 years
Patek 5235 / 5960 / 5980 / 5270 / 5204 / .... if the 5107 would have been 41 and not 39 I THINK it also would sell better
Richard Mille, Roger Dubuis,
The new Urban Jürgensen 11-C, a very nice piece .... 42 mm
I could go on and on and on