It's the modern web, whose motto seems to be: "making the easy difficult through the useless".

I didn't experience that before turning off ublock origin. It seems the YT-specific google tag manager[0] script is loading it, blocked by easylist for `/gtm.js`[1].

0: https://blog.youtube/static/blogv2/js/csp/gtm.js

1: https://github.com/easylist/easylist/blob/3d27d8f9f4752fda71...

They are hidden by default on certain platforms, and you need to scroll to see your position.

Some platforms (at least MacOS) hide the scrollbars by default if you’re using a trackpad.