Creating the xorg.conf.d file has fixed it for me, no more screen tearing.
This is on an old HP Pavilion g7 laptop with itel graphics running ubuntu mate 20.04.2
The laptop duel boots Win 7 where there is no screen tearing hence I knew it could do it.
I had tried several combinations of marco with and without compositor as well as enabling hardware acceleration and other settings in chrome, chromium and firefox, all still suffered some degree of screen tearing.
Fingers crossed we will get several more years of use out of the old laptop thanks to ubuntu mate.