If your line of thinking had been valid I think the automotive industry would have adopted it a while back. What you have in an EV battery pack is already a collection of Lithium Ion
CELLS, connected up to give the required voltage and capacity. A 375 volt EV battery is composed of multiple series sticks of 100 cells, connected in parallel, to give the required capacity. It is like a 12 volt lead acid battery, as used on most road vehicles. It is composed of six 2 volt lead acid
CELLS connected in series.
To get 30 kWH of capacity from a Lithium Ion battery requires 8108 3.7 volt cells.
Kilo watt hour (kWh) to Ampere hour (Ah) Conversion | EverydayCalculation.com
So you would have 81 parallel sticks of 100 cells to achieve this. This is what the EV battery is composed of.