I'm surprised too; in the Windows world, two decades ago, "skins" were popular and those essentially turned every single UI element into a bitmap. On the hardware of that time, their impact on performance was pretty minimal.
Of course, "every UI element is a bitmap" is not a good idea anyway, for other reasons, but seems to have someone become the norm for web and mobile.
Of course, "every UI element is a bitmap" is not a good idea anyway, for other reasons, but seems to have someone become the norm for web and mobile.