The frame doesn't look to me like a recent production frame for folding fat-tire ebike.
I have had owned quite a few folding fat-tire ebikes since 2017, research many different brands & manufacturers; never seen one with similar frame construction like that, never seen one fail like that neither.
Do you know the fabrication date/year of that frame?
The failure looks to be at the location of the frame weld, likely the rider took a significant hit prior to failure; something I've seen many times on aluminum (Cannondale & other) frames.
To generalize this to be another reason not to buy cheap ebikes is somewhat misleading.
The damage to the rear shock is likely cause my impact with the seat pillar after the initial frame failure.
Last edited by cat0020; 03-13-22 at 12:09 PM.