Is there a way to make Mac's spoken text sound more realistic?

When I direct the iPhone to read a browser page, it sounds fairly realistic. But when I do the same on a Mac (Spoken content > Speak selection) it still sounds like 20 years ago. Is there something I'm missing, or is semi-realistic speaking still not available as part of the Mac OS? It's not "accessibility" on the iPhone, it's a normal part of using the browser.