On the YouTube thing I've found their processing time varies, and the higher the resolution the longer it takes. This seems to be related to their system load but your ISP connection matters too; mine got 'throttled' recently and it took an hour to do what usually takes a few minutes
Once your vid is published, it begins as low-res and it may take some time to have high-res available. It will not usually default to high-res viewing until it's gotten several views, and even then it may not do it's best until you click on the vid's "settings" button and select the highest resolution option. Channel popularity plays a role here; those who have the most views get top resolution almost instantly while the rest of us don't. And their added compression means that whatever you see it will not be as good as viewing the raw file is.
If you expect better from "Alphabet-Google-YouTube" you'll be disappointed.
Phil