One major drag on current computer performance is the paging MMU which turns a simple memory lookup into indirecting over pointers 3 or 4 times.
Sure there is a "translation lookaside buffer" that caches this work, but it is a lot of transitors, is a venue for SPECTRE and MELTDOWN type attacks, etc.
One could dream of a new hardware and OS combination that eliminates quite a bit of this, but where would you get software to run on it? You will probably have a list of programs you like, such as "vim", "bash", "grep", "python" and all of those are built assuming you have an Unix-like or Windows-like API.
Put in that API and you have put all the bloat back in. If your goal was to make an OS that has different characteristics, you lost.
TBH, I still use SMTP a lot, and IRC as well from time to time.