Platforms like Hulu typically stream the earlier seasons in an upscaled HD format, but playback may automatically drop to 480p if your internet bandwidth is low.
If you're looking for the "All Seasons" collection in 480p, the main advantage is storage. You can fit the entire series (160+ episodes) into a much smaller footprint than the HD versions. futurama all seasons 480p
(which now exclusively streams Futurama in the US) offers a subscription. Most Hulu content streams in 720p or 1080p, but you can force 480p by limiting your browser settings or using a slow internet connection via throttling options. Platforms like Hulu typically stream the earlier seasons