# After having similar issues with some DEs not loading ~/.xinitrc, I avoided xmodmap altogether, went to /usr/share/X11/xkb/symbols and modified the key=>symbol mapping directly.
To do so, I edited the config file for my keyboard located at /usr/share/X11/xkb/symbols. For most keyboards, this should be the pc file.
After opening the file, I manually switched around Escape and Caps_Lock for their respective keys the result is shown below). As this affects how X maps the hardware to the key Symbol, it should work regardless of whether you're on GNOME or i3 or anything like that.
# https://unix.stackexchange.com/questions/199266/how-to-permanently-remap-caps-lock-to-esc-in-x11#426787
