You will need to install a user script manager extension to install this script.
Replace monaco with vanilla textarea.
Why? I couldn't represent others but I only wrote code in my local editor and then copied it into leetcode, so the heavy monaco editor in leetcode problem page is useless for me. This script replaces monaco with vanilla textarea, reducing the per page memory footprint from ~240 MiB to ~150 MiB. The specific affection depends on your environment.