Resolution is one part of quality
480p, 720p, and 1080p describe different vertical picture resolutions. 4K describes a higher-resolution format, but the source, compression, and device still matter. A high-resolution label does not restore detail missing from a poor source.
Why 300MB and resolution are different
A file’s size is affected by running time, compression, bitrate, audio tracks, and subtitles. Two 720p versions can therefore look and sound different. A compact download label should not be treated as a universal quality grade.
Use the actual viewing option
This website lists films rather than downloadable release files. Check the service you choose for available resolution, bandwidth requirements, audio, and offline playback. The catalog’s poster size and community rating do not describe the video quality.