x86 came out 1978,
21 years after, x64 came out 1999
we are three years overdue for a shift, and I don’t mean to arm. Is there just no point to it? 128 bit computing is a thing and has been in the talks since 1976 according to Wikipedia. Why hasn’t it been widely adopted by now?
Because there is no need from an address space or compute standpoint.
to understand how large 128bit memory space really is; you’d need a memory size larger than all the number of atoms in the solar system
In the rare cases where you need to deal with a 128bit integer or floating, you can do it in software with not that much overhead by concatenating registers/ops. There hasn’t been enough pressure in terms of use cases that need 128bit int/fp precision for manufacturers to invest the resources in die area to add direct HW support for it.
FWIW there have been 64bit computers since the 60s/70s.