Youtube is following the footsteps of Facebook and etc to provide a lite version. It is now in Beta and it is called Feather. However, to use it you will need to opt in. Don’t worry, you can opt out anytime.
The above is the Youtube Feather (Beta). Can you spot the differences in a Standard Mode?
Seems like the Annotation Editor is not in Feather and also, the site is striped off (almost all) of the fanciful things like playlist and share function.
Anyway, you can click the below link to activate this “Feather” feature.
Click Here to Activate Youtube “Feather” Feature