I can't speak to all of them, but the Pixel line absolutely does, and so do some other vendors.

At one point Samsung came with both Samsung Browser (chromium based) and Chrome preinstalled, but I'm not sure if that's changed in recent years.

Check the sales figures. The Pixel line is a very minor player, especially worldwide. The biggest vendors are Samsung, Xiami, Oppo, Vivo and Huawei. All have their own browsers. The Pixel line has 2% market share in NA and less worldwide.

Chrome dominates because it's better. People install it.

Chrome is the default on way, way, less than 50% of Android phones.