That's not correct. On my laptop, I can easily edit a 100 (one
hundred) MB text file, Emacs is almost as reactive as with a 1 KB text
file. Of course some operations take more time, e.g. a
query-replace-regexp on the whole buffer, but from what I see (on my
laptop it takes about four seconds, with a regexp) I doubt that it
takes more time than hundred query-replace-regexp in a 1 MB file, or
for that matter than doing this with dired on hundred 1 MB files.
I think it depends on content in those files as well as of size.
Try to edit some of those two files: https://github.com/amno1/Plato ,
possibly Plato.org. Don't just display them, but try to actually put
some text note in it or add/remove some whitespace or whatever. Jump to
some paragraph and insert a new line and see how long it takes. Then try
to do same in Atom text editor.
My Emacs takes quite some time even to add a white space char while Atom
has not problems whatsoever. I run on 6700K i7 cpu + 32 gig 3000Mhz ram.
I don't know what the problem is, if it is just my Emacs config or
actually underlaying data structure (Gap buffer vs linked structure
optimized for changes - their "Superstring").