Try using a large blocklist[1] in your hosts file and installing umatrix[2] and/or ublock origin[3] to block garbage scripts from loading. I don't know if that will help, but that's what I'm doing and Firefox is as fast or faster than Chrome.
[1] https://www.google.com/search?q=hosts+blocklists
[2] https://addons.mozilla.org/en-US/firefox/addon/umatrix/
[3] https://addons.mozilla.org/en-US/firefox/addon/ublock-origin...