Whether top or front loading h-axis washers came to dominate or are major share of local market post WWII largely came down to home design.
In UK with trend of fitted kitchens where appliances are often built in under counter/work tops, obviously any sort of washer that opens from top is non-starter. Thus front loaders dominate.
OTOH in France, Germany and other areas including parts of Eastern Europe where laundry appliances aren't always built in under worktops, top loading machines have good market share. French in particular those living in urban areas love themselves top loading h-axis washers. Kitchens while yes on often small size, things aren't always all built under worktops. There is usually a small spot perfect to fit an top loader.
Top loading h-axis washers are also incredibly popular with maritime (boat) owners. There is benefit of savings that come from low detergent and water use plus things will fit into narrow spaces.
MieleUSA has a division just for ships/boats and is only place one can (or could) get a Miele toplader outside of Europe.