Revert to old Youtube UI
A simple script that for the most part returns the old layout where the comments are below the video and the recommended videos are on the right and also applies the right proportions.
Update:
I am unable to check and maintain the code as my YouTube page reverted to the old look.
If you have the new look feel free to modify the code as you wish and share it.
Last time I used this code it worked fine with 16:9 videos, other aspect ratios are less likely to work aswell.
I used tampermonkey on chrome with this script and also tested it on edge and firefox. While it worked in firefox it did take a while before the script ran.
The script changes the flags to not use the new styling however the proportions do not seem to be affected by the flags and need to be changed independently.
I also saw some users saying the script no longer works due to apparent changes in youtube which I am unable to check.
