So what you’re saying is that … we can make up whatever number and standard we want? … In that case, would you like to buy my 2 Tyranosaurusbytes Hard Drive?
Nah, the prefixes kilo-, mega-, giga- etc. are defined precisely how hard drive manufacturers use them, in the SI standard: https://en.wikipedia.org/wiki/International_System_of_Units#Prefixes
The 1024-based magnitudes, which the computing industry introduced, were non-standard. These days, the prefixes are officially called kibi-, mebi, gibi- etc.: https://en.wikipedia.org/wiki/Binary_prefix