Several years ago, I was an assistant housekeeping supervisor in a hotel chain. Many hours each day were spent folding the sheets, pillow cases, towels, etc. The hotel required special folding for many things. And only had queeen and king size beds.
I leared very quickly how to fold king and queen fitted bottom sheets. Now it is just a habit for me do fitted sheets that way. It takes the same amount of time to fold fitted as it does the flat.
Just watched the YouTube video. That is exactly how I do my sheets, but only much faster.