"A full set of cups driven by a motor whose power claim is mostly marketing."
The 900W is 'peak power,' a theoretical maximum before the motor stalls. In practice, this will perform like a blender with a much lower continuous power rating, likely in the 300-400W range.
This is a justifiable purchase for someone blending soft fruits and protein powders who values having multiple to-go cups more than blending power. At this price, it's a low-risk entry-point for simple shakes.
Anyone intending to regularly blend ice, dense frozen fruit, or fibrous vegetables should invest more. The motor will likely struggle and wear prematurely under such loads, and the buttonless design offers no control.