搜了一下，说 Pixel 一代 可以终身原图上传，Pixel 二代原图上传只到 2020 年，这好像又成为了我买 Pixel 一代的理由
> One of the great features of last year's Pixel phones was the promise of unlimited photo backups at original quality to Google Photos. This differentiated from the unlimited "high quality" backups on non-Google phones. For the Pixel 2 and 2 XL, this feature is still available but with the small limitations that it's only for photos taken before the end of 2020. Any pictures taken after that will be backed up with the same "high-quality" option that other devices have.