Normally the idea is presented as "short-lived branches", with short meaning "as short as possible" e.g. days instead of weeks. At that point it's non-controversial and the argument about peer-review vs. no-peer-review can be separated from "how do i get this back into the mainline without breaking everything?"

Also I merge master into my branch several times a day just as a matter of habit, because yeah it's usually better to discover conflicts ASAP instead of two weeks after they've happened. Keeping your branch short-lived also helps prevent conflicts in the first place.