Complex sentence: Though the return of fuller-cut trousers in the 1940s revived suspenders, they did not dominate over belts again to the same extent, however in the UK they remained the norm to wear with suits and dress trousers.
Split into simpler sentences: Though the return of fuller-cut trousers in the 1940s revived suspenders, they did not dominate over belts again to the same extent. However, in the UK they remained the norm to wear with suits and dress trousers.