My brain is fundamentally incapable of very basic computation types even a plain 6502 could do. It is slow and unreliable. Deterministic evaluation can only be done symbolically, slowly and even then it is failure prone.
It is likewise unequipped for interfacing with information systems or external equipment in any meaningful way. Its extensibility is limited more than it needs to be. Our auditory apparatus, is capable of sufficiently varied IO that we should be capable of directly sharing various digital data at practical rates, among other options & apparatus.
My memories corrupt themselves trivially over time without any form of error correction. That is a disability that affects every human. My eyes will fail and decay as I age. They will do so long before I have no use for them.
I do not have control over large parts of myself where I should. I live in a blackboxed system that actively spites me.
One's flesh puppet is a tool, so are its various organs & components, and they are not the epitome of perfection. You already rely on those to exist. The only difference is that they are mostly beyond your ability to modify.
You also seem to believe your own flesh will not betray you and rot, despite the fact it demonstrably does so for millions every day. The dystopia you fear is already here. It has been for thousands of years.
This flesh puppet of mine refuses to reconfigure itself according to my will, despite the fact that the overwhelming majority of the mechanisms required to enable such an act are present and actively used - beyond user control - for decades.
Incidentally, the self-modification problem is specific to humans and certain other kinds of life. There *are* animals capable of purposely modifying themselves, though that is limited in a number of ways I would still deem insufficient.
I already addressed the issue of forced removal of apparatus.
