The Antminer B3 situation appears different from other ASICs which have declining ROIs. I recall the B3 was advertised to be an ASIC for mining Tensority (BYTOM), and the algo was to be mined with Bitmain B3 hardware and firmware with options of benefiting from AI mining/processing opportunities.

However, it would seem that the ‘ASIC’ chips in the B3 are not efficient on the Tensority algo, and Tensority can be mined on non-B3 machines.  

The Antminer S9, L3 etc are very efficient on the algo they were designed to mine and that is why buyers purchase these ASICS. Buyers can assess declining returns depending on units shipped and the efficiency of the miner.

The B3 is not even efficient at mining Tensority. It is not fit for purpose. It appears to be a box stuffed with non-specific ASIC chips to clear inventory, and not a true ASIC.

Therefore, proper disclosures were not made to purchasers of the B3  and a reasonable calculation of risk could not be made.