All browsers do this. Firefox implements around 88 properties (30 of these are "logical properties", which aren't exactly new properties) that Chrome doesn't[1] and Chrome implements around 68 properties that Firefox doesn't[2].
The numbers are a bit skewed here. My method of collecting the list of "properties that Firefox implements" included preffed-off properties, but the same is not true for Chrome, so for example the `grid` property shows up as implemented in Firefox but not Chrome even though both have it behind a pref/flag.
However, there are some properties implemented in Firefox without being behind a pref (ruby-align, scroll-snap-foo, image-orientation are examples).
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I do feel that in general Blink does push a lot of nonstandard (or not on the standards path) features into the web at times. But I don't have anything to back that assertion up.
Blink is being interoperable in this particular case.
[1]: https://manishearth.github.io/css-properties-list/?stylo=sho...
[2]: https://manishearth.github.io/css-properties-list/?stylo=sho...