when you pinch and zoom does the screen zoom or the web page contents?
Only the webpage zooms. Doing this gesture use to increase the font in the old Safari. Now it does a zoom like if you pinch to zoom on iOS. You can also double tap to fingers to make it smart zoom. Does that work for you?
Found a fix. Using "Get Info" for Safari, make sure it's set to 64-bit mode. Mine was set to 32-bit mode and once I changed it to 64-bit mode, pinch to zoom worked fine again.