Simple script for reduce memory consumption in GNOME 3. Tested on Fedora 29 Worksation with GNOME 3.30 version.
wget https://raw.githubusercontent.com/tim77/reduce-gnome3-ram-usage/master/reduce-gnome3-ram-usage.sh
Run as regular user (non root):
sh reduce-gnome3-ram-usage.sh
Reboot.