Miele's 4XXX series washers had 4.0 cuFt capacity (claimed).
The W1 series claims 2.6 capacity
Miele like many other brand of washers from Europe get away with greater capacity washers but keeping same overall footprint (almost0 by making drum deeper and bit wider. Miele did this with their W1926 and W1966 among others. This bumped capacity up from 5kg to 6kg
Miele claims their W1 series can handle up to bit over 17.6lbs of wash. This compared to SQ residential front loaders that claim 18lbs.
Unlike their tried (and failed) uber sized Miele 4XXX series washers, the W1 series offers greater capacity but still will work with European laundry situations. The larger W4XXX would not.
Ironically Miele's "Little Giant" washers are rated for slightly less capacity (15lbs) than W1.
https://www.designerappliances.com/miele-pw6068ss.html
It's worth noting Bosch also entered and quickly withdrew their uber capacity front loader (NeXXT). That washer claimed 4.2 cuFt capacity.
It just doesn't seem as if European laundry machine brands do uber sized front loaders well for domestic machines. Commercial, OPL and laundromat is another matter.
Here is a clip from Miele Canada discussing front loader capacity.
Personally feel unless one is going to be washing king sized bedding such as duvets or eiderdowns at home, about 18 pound capacity is more than sufficient.