Their ads and search are their bread and butter if I'm not mistaken. So even if all you can do is change their browser's default engine every little bit helps. I myself have uninstalled chromium browsers and switch to FF/LibreWolf. I still have Google Authenticator but that will take me longer to kick with its 30+ entries. I'd love it if I could find out which services cost them money and heavily use those for the time being.