Lower storage density chips would still be tiny, geometry wise.
A wafer of chips will have defects, the larger the chip, the bigger portion of the wafer spoiled per defect. Big chips are way more expensive than small chips.
No matter what the capacity of the chips, they are still going to be tiny and placed onto circuit boards. The circuit boards can be bigger, but area density is what matters rather than volumetric density. 3.5" is somewhat useful for platters due to width and depth, but particularly height for multiple platters, which isn’t interesting for a single SSD assembly. 3.5 inch would most likely waste all that height. Yes you could stack multiple boards in an assembly, but it would be better to have those boards as separately packaged assemblies anyway (better performance and thermals with no cost increase).
So one can point out that a 3.5 inch foot print is decently big board, and maybe get that height efficient by specifying a new 3.5 inch form factor that’s like 6mm thick. Well, you are mostly there with e3.l form factor, but no one even wants those (designed around 2U form factor expectations). E1.l basically ties that 3.5 inch in board geometry, but no one seems to want those either. E1.s seems to just be what everyone will be getting.
Lower storage density chips would still be tiny, geometry wise.
A wafer of chips will have defects, the larger the chip, the bigger portion of the wafer spoiled per defect. Big chips are way more expensive than small chips.
No matter what the capacity of the chips, they are still going to be tiny and placed onto circuit boards. The circuit boards can be bigger, but area density is what matters rather than volumetric density. 3.5" is somewhat useful for platters due to width and depth, but particularly height for multiple platters, which isn’t interesting for a single SSD assembly. 3.5 inch would most likely waste all that height. Yes you could stack multiple boards in an assembly, but it would be better to have those boards as separately packaged assemblies anyway (better performance and thermals with no cost increase).
So one can point out that a 3.5 inch foot print is decently big board, and maybe get that height efficient by specifying a new 3.5 inch form factor that’s like 6mm thick. Well, you are mostly there with e3.l form factor, but no one even wants those (designed around 2U form factor expectations). E1.l basically ties that 3.5 inch in board geometry, but no one seems to want those either. E1.s seems to just be what everyone will be getting.