utube doesn't work like that.
No matter what bitrate or quality you upload it at...it delivers to the viewer whatever it thinks will present a seamless experience.
You can upload at whatever the max quality is....if whoever is viewing it at has a poor connection, youtube downrates the delivery to what their connection can support.
The video still exists at utube in all its original glory (mostly).
But the delivered bitrate and quality also depends on the users connection.
Compression on your end before uploading? That will never, and cannot, result in a better image.
Compression = some bits/quality tossed away, in favor of filesize.