Unlike other browsers, it can’t be said that Google Chrome’s focus is on privacy.
However, the DNS system has historically required computers to perform DNS lookups (matching a URL to an IP address) unencrypted, which means anyone from your ISP to bad actors could see what websites you’re visiting.
DNS-over-HTTPS changes all that by encrypting the DNS lookups your browser performs—essentially shutting out ISPs from knowing which sites you go to (the websites themselves can still identify your computer by its IP, however).
In other words, Google adding DNS-over-HTTPS to Chrome, the world’s most popular browser, is a major privacy win.
However, if you want to flip the switch on it now, you can (via ghacks.net): Now, provided your DNS server supports Secure DNS, DNS-over-HTTPS will be enabled in Chrome, making your internet browsing that much more private.