[Isthatablackgsd]

YouTube will re-encode videos to optimize their playback experience. Which means there will be a generational loss in the re-encoding. YT have maximum requirements for their playback. If the source file exceed those, they will lower it.

Handbrake is useful for lots of things. My partner have to upload his dissertation defense video and the university have strict requirement of the formats. He used Handbrake to convert his video to their formats of choice. It works well for him on his aging 10 years old MacBook Pro (upgraded the HDD to SSD years ago).