only if you are the only one doing the obfuscation.

It's why tor browser is set to a specific dimension (in terms of pixel size), have the same set of available fonts etc.

And yet you still stand out if you use tor.

yes, and it's because not enough people use tor-browser (i meant the browser, not the network).

But if privacy is truly the desired goal, the regular browser ought to behave just like tor-browser.

Tor Browser safe mode. That is one of few ways to defeat that fingerprinting thing.