in fact the weather in london is nowhere better than singapore. there is so much rain/wet/dirty road there. and yet those english men wearing english shoes with leather soles???
You answered your question yourself regarding material durability lol.
Leather soles, esp oak bark tanned are very tough. With a proper rotation and rest, a good leather sole can last for years, even in inclement weather. Emphasis on Rotation and Rest however.
Just dont expect the same wear characteristics as a rubber sole but neither does that mean that one material is of magnitudes superior than the other.
However, some of us topy our soles to maximise longevity for the sole(lol) advantage those Englishmen have that we dont. They are just a stroll away from the factory while we have the glorious Atlantic and subsequent shipping costs to contend with when the inevitable day comes that resoling is necessary.
A mild case of Penny pinching that's what it is but shoe soles are made to step on shiat, you dont have to baby them.