What are electrons really made up of? Any suggestion?
The electron is a fundamental particle. It never decays into pieces nor can it be broken into pieces to investigate any components. You just have to accept we cannot describe any particles which combine to become this particle. This is the limit of our technology.
The Structured Atomic Model accepts 2 fundamental particles, electron and proton.
Someone made this comment to my post:
There is no such thing as a "fundamental particle". There can not be any limits in micro-cosmos. Even if one refer to "the limit of our technology", it is only the "technology" that is limited. An electron must consist of something, and this something must then consist of something even smaller and so on in eternity .....
I am justified to call it a fundamental particle simply because we are unable to break it. Based on that limitation, one can suggest any cascade of subparticles having any characteristics but with no evidence for any of them.
Particle colliders broke protons and neutrons into 3 subparticles each but these 2 have different charges so the sets of 3 were given different names. That destruction lead to the game of the standard model and proposing a Higgs boson to impart mass to another particle. That standard model contributed nothing compared to the structured atomic model which makes a connection to chemistry while the standard model does not. I suggest breaking a proton accomplished almost nothing worthwhile.
The 'must be smaller to eternity' is metaphysics, not physics with acquired knowledge by observation.