The vast majority of people who buy Kits from different places are beginners who want quick results, with all the necessary components in one place, selected, with very clear assembly and adjustment instructions, but who often cannot objectively evaluate the quality and consistency of the products. They will be satisfied that they managed to create something functional, useful, by themselves. QC doesn't really matter in this situation either. Some assemble a Kit and are satisfied, they stop there and do not continue studying in depth.
I personally prefer to buy with the money how much a complete kit costs, as many second-hand, functional or defective microphones as possible and to mod, repair, build, experiment, study, etc. My satisfaction is much higher (the investment is justified, rewarded,
or not
)
The big problem (when it's a real hobby)
is that you become addicted and you don't stop, you buy without needing!! GAS.
But that means passion, hobby.
DIY.