Because I thought that if the battery is connected to the 5v pin, when the voltage in the battery drops to about 3.5v, the module will stop working, and if it is connected via a stabilizer and to the 3.3v pin, even if the battery has 3.5v, it would still work..
but if it doesn't matter because it will work the same way, then there is no point in me buying a stabilizer if it is unnecessary